Tell me a story(maybe it's true)
by Insane. Certifiably
Summary: How Killer Frost learned to love, as taught by a dozen lives Barry Allen could have lived.
1. When in Rome

**I know the show won't go this route, they'll bring in Killer Frost in an entirely different way, but I like playing with the possibilities that having a breech to other universes opens up.**

 **Trigger warning, I think, for the whole entire piece, because Zoom is not a nice person in public or private.**

 **Flash and its related components belong to the CW and DC comics, not me.**

* * *

No matter how many times she saw it, the sight of Zoom without his mask on was no less shocking. With it on, he was darkness and death and the double-toned voice, the face people expected a monster to have, cloaked in blue lightning.

But when he didn't have it on, he was handsome, green eyes and tilted smiles and hair in disarray. The thought crossed her mind occasionally that he was more of a monster like this simply because he didn't look like one. He looked like anyone on the street, and that was probably why he wore the mask rather than a helmet as the Flash did. He wanted to be more, to be the best and the only. He would be the fastest man in existence, by killing off everyone who posed a challenge to that title if necessary.

He was standing at a workbench when she came in, mask tipped back to pool around his shoulders, brows furrowed in concentration as he transferred a solution from one flash to another. She leaned against the doorframe, arms crossed over herself, and watched him work, faster than anyone else ever could. Solutions vanished from beakers and reappeared in test tubes in a haze of blue lightning, until suddenly it was still.

"Killer," he greeted, lifting his hands toward her. She went willingly to him, relaxing as his warmth chased away the ever-persistent chill, however temporary that relief was. She'd had another name once, but Zoom never used it and he was the only one whose opinion mattered.

"I think I found something," she said into his chest.

"Hmm?" his arms came around her , pulling her in more securely, and he tucked his face into her hair, "Have you found the Flash?" The edge in his voice was only barely buried below the warmth and she wrapped her own arms around his middle.

"I found something," she answered, "a way he could have gone."

Zoom slipped a finger under her chin and tilted her head up to meet his eyes. "Where?"

"Fourth and Main," Killer Frost replied, "inside the bank."

The hand he'd had under her chin pulled his mask back up and over his head while the other tightened around her. She had that instant to brace herself, drawing her feet up as the lightning surrounded them, counting her heartbeats until they arrived.

Zoom set her back down on the marble floor, and people started to flee for the exit. Killer Frost saw someone reaching into his pocket and stretched out a hand, sending spikes of ice flying through the man. She didn't need the gesture, but it made the whole thing more dramatic and would lull the police into a false sense of security if they ever managed to capture her.

"Where?" he was back to the double-tone that he always used when not in his lab.

"Up there," she pointed one hand up to the railing on the second floor. Raising the hand higher, she shot a bolt of ice into the space. Something rippled in the air, and the ice bolt didn't reach the ceiling.

"See that no one disturbs us," he said, and vanished, reappearing upstairs a second later. She turned and layered ice over the doors, blocking them off until it would take a battering ram minutes to get through.

She'd had the thought once, that she might be able to kill Zoom, but before it could even become a fully formed idea, let alone even the beginnings of a plan, she had tried to imagine life without him, without his warmth chasing away the chill, without his voice lending her purpose. She'd failed utterly. Zoom had become her world, and she didn't know how to lose him.

He was leaning both elbows on the railing when she made it up, watching the space about five feet in front of him contort. Killer Frost leaned against him, and he adjusted almost automatically, slipping an arm around her to tug her close, all the while not taking his eyes off the anomaly.

"This was what it looked like the day the Flash disappeared," Zoom said, he made a gesture, and lightning shot forward through the portal, disappearing as it surged.

"Where does it go?" she asked. She had realized it was a portal when the ice hadn't reappeared, but she hadn't been able to figure out where it led. Zoom could see things that other people were too slow to catch.

"The same way the Flash went," he replied, "And now you, my lovely Killer," in the tone she could hear the smile, even if nothing was betrayed under the mask like death, "are going to go through it."

He slipped away, and she felt the cold descend again immediately, but he was back again in a blur of blue lightning. She felt an arm go around her, and movement, and then they were hurtling through the air. It was not a smooth journey, they bumped around, ricocheting off things she didn't dare open her eyes to see.

And then it was over. Zoom's gait smoothed into the one he used on flat ground and then stopped. There was ground beneath her feet and Killer Frost opened her eyes and looked around. They were standing in an alley, building rising up on either side.

"What now?" she asked.

The mask disappeared for an instant, and he took her chin in a grip like iron, tipped her face up to search her eyes. He kissed her then, harsh and possessive. "When he's dead, let me know," Zoom breathed against her lips, "and I'll bring you home."

And then he was gone, the alley alight with blue lightning for the span of a heartbeat before she was standing there alone.

Killer Frost wrapped her arms around herself, the chill already sinking back into her bones in Zoom's absence. After a moment's deliberation, she picked an end of the alley and started walking.

It let out onto a small side street, and she strolled along the edge of it, her fingers leaving trails of frost on the windows of cars as she dragged them languidly along. By the time she found a main road, people were starting to whisper and point, but Killer Frost ignored them for now. She needed something bigger, more people would draw the Flash faster and she could be home in Zoom's arms by the end of the day.

Someone stepped into her way, and she laid a hand delicately on their shoulder. The obstacle turned blue and fell away, and she continued walking, leaving a scramble in her wake. Good, she wanted to make as much noise as possible, and every little bit helped.

As she walked, she noticed this Central City was a little more low-tech than her own, and the towers of STAR Labs were different, somehow. More broken than Harrison Wells' gleaming model in her own world.

She had to freeze three more people before she found what she was looking for. The sign at the top of the doorway said Police Station, and it would bring the Flash running. But she hesitated at the door, stopping before she touched it. She wasn't bullet-proof, and no amount of ice would save her if a bullet caught her wrong. But Zoom was depending on her, so she pushed open the door.

A receptionist sat up. "Can I help you?"

Killer Frost leaned over the desk and smiled her most disarming smile. "Yes, I'm looking for the Flash."

"Why?" she had attracted the attention of an officer coming in, coffee cup in his hand, "is something going on? we haven't gotten any reports of a meta-human attack."

She stretched out a hand, and the coffee was frozen solid by the time it and its owner hit the floor. "Now you have," she said. Turning back to the horrified man behind the desk, she added, "call the Flash."

He was shaking his head before she even finished the sentence. "I can't," he said.

A second later, he was howling in pain as she blasted him with ice. "Get him here," she commanded, "Now."

"Hands up!" commanded another voice, this one full of authority. She turned her head, not bothering to adjust her posture, as though she considered him a slight annoyance at best.

This one was older, balding and dark-skinned, wearing the plain-clothes of a detective rather than the stiff uniform of an officer. "I said put your hands up!" he repeated.

"Make me," Killer Frost answered. She pushed herself off the receptionist's desk and sauntered toward him, letting ice grow in her wake at every step, coating every object she neared. The overall effect was both demoralizing and would make it more difficult for the Flash to keep his balance later.

Zoom had once made her coat the walls and floors of his lab with ice, then spent an utterly undignified few hours falling over as he taught himself how to run on it, but the net result was that she could use her ice without having to try and keep track of where he was.

"I will shoot," the detective warned her.

A well-placed blast of ice coated his gun until he couldn't get it to fire, no matter what he did. He took one look at it and started backing up, bellowing a warning as she went.

"Where is the Flash?" she seized him by the front of his coat, lifting him nearly off his feet. She didn't bother freezing him yet, she needed this one alive until he either gave her what she needed to proved to have no use.

There was a blur of lightning, and then a man in a red suit was standing there. The costume was different on this Flash, he wore a mask rather than a helmet as the Flash she was more familiar with, and his head was shaking, just enough to blur his features, but the lightning was the same gold the Flash in her world had used. This was not the Flash she had gone looking for, but Zoom would be doubly pleased if he heard she had managed to kill two.

"Put him down," he called out.

And it was Zoom's double-tone. The double-tone that the Flash in her universe had never bothered to use.

The sound took her off-guard enough that she actually stopped moving, opened her fingers and let the man drop to the floor, the ice bolts she was planning fizzling into nothingness before she could shoot them. Had she not seen the lightning, she could have mistaken this for Zoom testing her.

"Uh, wow," he sounded suddenly young, "I didn't think that was actually going to work."

No matter that this wasn't the specific Flash she had been sent to kill, it was a Flash and that would be good enough for Zoom. She smiled, showing as many teeth as possible. "It didn't." The ice bolts she had held back now went shooting out as she raised her arm.

The Flash disappeared in a streak of gold lightning, and the man at her feet vanished as well, reappearing among the desks. "I've got this," Flash told the officers there, never taking his eyes off her, "make sure this area is evacuated safe-" the tail end of the word blurred off as she shot more ice and he vanished again. She turned with the lightning, building a wall around herself. The crack of gunfire resounded through the room, but she simply thickened the shield, closing off every exit the Flash tried until he was forced to face her.

The trail of gold led to a pillar and didn't emerge out the other side, tell her exactly where he was and how he was trying to hide. She shot it with ice, and there was a certain satisfaction in the way the little shocks of lightning, produced as he flinched, lit up the wall on the other side of the pillar. Flash popped out from behind, only a few steps away. She blasted the spot, but he was already gone.

"Why are you doing this?" he called out, voice resonating through the station and leaving her turning in circles trying to figure out where he was. This should not be this difficult.

"I want you dead," she snapped back, "come out so I can kill you."

"No thanks," came the reply, still Zoom's double-tone, "I kinda like being alive."

She found him, halfway hidden behind a spot where the wall thickened. In the way he had a hand pressed to his ear, she knew he had accomplices, people on the other side directing his actions.

She tilted her head, and encouraged the wall to grow around him. Flash only barely slipped out of the pincers of her trap, sliding on the ice underfoot. He passed close enough that she felt the crackle of the lightning, but he still hadn't done anything, seemingly content to let her tear up the police station without trying to do anything about it.

"It could kill her," she heard him argue back to whoever was on the other side of the line.

Ice poured out from her, following the encompassing gestures she made as she changed tactics. If she couldn't run a spike through him, she would shrink a sphere until he was caught. The walls surged higher and higher, closing toward each other at the top until the light abruptly dimmed as everything outside was gone.

Flash's lightning sparked, the light bouncing off the ice as she poured in more and more, pulling the circumference inward.

"Alright," Flash said, and then the lightning was headed directly for her. She flung up both arms in reflex, crystallizing a shield in front of her. It was cold enough now that the fog of Flash's breath streamed behind him along with the lightning as he inscribed a circle around her.

She realized what he was doing as her ears popped from the change in pressure and thrust out a hand, pouring ice through the space in front of her and held it, even as he took the circle tighter and tighter around her. The only sound now was his ragged breathing, as she had to hold hers while the air left the circle. She just had to hold on, put enough ice on him to stop the funnel before she ran out of air. She just had to outlast...

And then she knew blackness.


	2. On Monsters and the Masks They Wear

When she woke, it was warm, she was lying on something hard, and her whole body felt heavy, especially her head. "Where'm I?" she slurred the words, trying to stir herself.

"Hey," a male voice, and she forced herself up. There was a blonde man standing there, holding a notebook and a pen. There was a badge clipped to one hip and a gun holstered at the other. Police.

She thrust out a hand at him, reacting without thinking and nothing happened. Killer Frost pulled her arm back in and stared at it, then tried to summon ice, pull in heat. Nothing worked, and she realized for the first time she didn't feel so cold. Zoom was nowhere to be found, didn't have her close so she could draw off the warmth he gave off, but she felt like she did when he was. No, she felt even warmer than that.

The beginnings of desperation growing in her chest, she searched her surroundings. She was in a box, made of some kind of plastic, one wall transparent. There was enough room to pace a step or two, a mattress with blankets, but nothing more than that.

"Hey," her visitor rapped on the wall, drawing her attention back and she whipped her head up, chastising herself for letting her guard down, for not remembering he was there. She was helpless now, they could do anything and she couldn't freeze them in their tracks anymore.

She fought the instinct to draw her knees up and hide. She would not be weak. It took her a few seconds to draw up enough energy to force herself to her knees, and then her feet, fighting the heaviness in her head that made it feel like she was thinking through cotton wool.

"Detective Eddie Thawyne," the blonde man said, not looking at her, "August seventeen. Interrogation of metahuman with freezing powers." He flipped open his notebook, "Let's begin with your name."

"Killer Frost," she replied, clear and cold.

He stopped writing, looking up at her. "Your other name. The one you had before the particle accelerator exploded."

"My name is Killer Frost now, Detective Thorn" she shot back, "that is the only name that matters."

"Thawyne," he corrected automatically, writing that information down. "Alright. Killer Frost. Why did you attack the police station?"

She raised and lowered one shoulder in a careless shrug. "It was the fastest way to draw out the Flash. I need him dead, so I had to find him."

"And why do you need the Flash dead, exactly?" the detective asked.

She stared at him, and he kept the contact right back. In every world, it seemed, there was no warmth in the police, he was cold and unflinching as a brick wall. And they called her the cold one. "To get home," she said at last.

"I don't suppose you'd be willing to tell me where you came from or why you need to get back so desperately you're willing to walk into a station full of armed police officers to try to accomplish that," Thawyne persisted, "or how killing the Flash relates to you getting home."

Killer Frost continued to stare at him, projecting as much hostility as she could from a box that may as well be a padded cell.

"Of course not," the detective scribbled down something else on his notepad, "Anything you want to volunteer?"

"You should let me out now," she said, "or you will regret it." Zoom would kill them all when he came for her, if she didn't get out and do it first.

"Alright," he wrote something else down. "In the meantime, those cuffs will keep your heat loss in check. At least until we find a better solution."

It was not just keeping her warm, it was overloading her, keeping her powerless. All she had to do was kill the man in the red suit, who trailed gold lightning when he ran, and Zoom would take her home, free her from these restraints. She just had to remember that.

Thawyne flipped the notebook shut, tucking it away, and started toward the opening she could see behind him. He took two steps, then turned back. "Almost forgot. Cisco wanted me to ask one last question: what do you want for dinner?"

She shrugged, equal parts not trusting her throat to work if she had to speak and not caring what they fed her.

And he walked out, leaving her alone.

She had plenty of time to think in that box. They fed her three times a day, or so she thought without any accurate way to measure time, and arrangements were made to allow her to use the bathroom, but mostly she was just left to stare at the four walls with nothing but her thoughts.

Invariably, they kept wandering back to Zoom. She wondered what he thought of the fact she hadn't returned yet. Was he looking for her? Or did he just think it was taking longer than anticipated?

Previously, when she had needed to wait for long periods of time, she had her powers. She could make snowflakes dance at the tips of her fingers, write in icicles, build entire cities in miniature out of ice, crush them, and start over, building atop the rubble until the whole thing was catacombs ready to topple at the slightest brush. But now she had nothing. They had made her nothing.

She saw the detective again a few times, and the man with shoulder-length hair who said his name was Cisco and whose face had fallen when she introduced herself as Killer Frost.

"You married to that?" he'd asked.

She'd fixed him with a stare, that, where she not reduced to this, would have cemented his feet to the floor and chilled him to his bones. As it was, he'd backed quickly away, and she was surprised to feel a tinge of regret when he was gone. She could hear others, distantly, sometimes catch glimpses as the cells were rearranged, but there was no sure way to communicate, and she was left alone.

She picked at the cuffs constantly, trying every variation she could think of to get them off. They resisted everything she could throw at them, she had nothing with which to pick the locks on them, they wouldn't break when she slammed them against the wall, though that action brought Cisco running again. He did nothing more than stand outside, watching her slam the cuffs against the wall over and over again, until her bones were ringing and she finally gave up, sliding down the wall to sit on the floor. She expected him to leave after that, but he hadn't. Instead, he sat down cross-legged outside the glass wall, and didn't say anything until she turned her head.

"Why do you want," there was a breath of a pause where he censored out the Flash's name, "the Flash dead?"

She didn't mean to say anything, but the constant warmth she was under and the isolation had wrecked havoc on her self-control and the words came bursting out. "Zoom told me to," she confessed.

Cisco scooted closer. "Who's Zoom?"

She let the knowledge draw her mouth up into something like a smile. "The fastest man alive," she told Cisco, "in every universe."

He arched a disbelieving eyebrow. "Faster than the Flash?"

She let that disbelief slide, because he had never seen Zoom, didn't know how fast the man was and would be. "Yes," she told him, "faster than anyone."

Cisco's eyebrows raised at that, but after a few more comments, she was left alone with her thoughts and the cuffs once more.

A few hours later the cells moved again, but she didn't bother looking up from the cuffs. It was about time for a meal, it was probably just Cisco with more Big Belly Burger.

"You're going to ruin your fingers like that," a double-toned voice observed, and she jumped up, Zoom's name dying unsaid on her lips as she saw Flash standing at the control panel, one red-gloved hand still on the door lock.

"So, Killer Frost," said the Flash, stepping forward to stand in front of the transparent wall separating her from her target, "who's Zoom?"

She drew herself up, dropping her hands to her sides. Somehow, the fact that this version of the Flash sounded like Zoom felt like a betrayal, and she refused to give him the satisfaction of seeing her unsettled by that.

"A speedster," she answered, "faster than you can imagine."

"If he's so fast," Flash asked, "Why didn't he come kill me himself?"

"He didn't know the portal would stay open," she answered, "he couldn't stay here for longer than it took the breech to settle back down."

"Breech?" repeated the speedster, standing a little straighter.

She refused to say anything. If they didn't know, she wasn't going to tell them Zoom's secrets. He'd trusted her, and she could not break that.

"Who is he to you?" Flash asked. The speedster was leaning against the transparent wall now, arms crossed and one foot looped over the other ankle, utterly at ease. It would be maddening, for him to be so close and relaxed, just out of reach, except that she had learned the same technique from Zoom and used it innumerable times to set people off their guard.

Killer Frost opened her mouth to reply, then stopped, trying to think of the right word to describe what Zoom was to her. Boss didn't quite sum up their relationship. Boyfriend was... she tried to apply the word to Zoom, and it slipped off like water, too gentle and soft for everything Zoom was. Friend? But that wasn't deep enough, not for everything he had done for her after the accelerator explosion, not for everything she had done for him in return. But that was the answer.

"He gave me my name," she answered finally, the words coming as she thought about it. "A few months after the accelerator exploded, I got my powers," she raised her hands, showing the cuffs, "and I was lost. I couldn't touch anyone, didn't know what to do, and I was so cold. Zoom gave me my name, gave me purpose again, and made me feel like I wasn't lost and freezing and alone. I owe him everything."

Flash tipped his head sideways on the glass. "You love him."

It wasn't a question, but it demanded an answer anyway.

"I-" she stopped. It wasn't that she had never thought about this, but the idea of Zoom didn't quite fit itself to the flowers and chocolate picture the word 'love' made. She had played with the words too many times to count, fitting them to Zoom in the dead of night while he was asleep, but she had never worked up the courage to say it to his face, frightened of the reaction he would have. "Yes, of course I do." But by the bit of his face she could see, he had caught the fact that her answer was shakier than she would have liked it to be.

"How long are you going to keep me here?" she asked, changing the subject abruptly.

Flash ignored the question for a moment, his eyes raking over her face. The feeling was oddly like when Zoom would look at her, like he was testing for something she couldn't have named even if pressed. She had opened her mouth to ask again when he spoke. "Will you try to kill me again if we let you out?"

She couldn't say anything to that, he already knew the answer.

The speedster looked down at the floor, and when he looked up again, the constant vibrations that had obscured his face had stopped. Though he still wore the mask, that didn't matter, not when she knew that face better than she knew her own now. Killer Frost gasped and flew to the transparent wall to press both hands against it.

It was Zoom; Zoom's green eyes and strangely young features, and she realized abruptly that she hadn't seen what color lightning he made, she had simply assumed it was Flash because he was wearing the red suit. It would be exactly like Zoom to take his enemy's costume as a trophy, to flaunt the slower speedster's failure while they remained in this universe.

"Zoom," she breathed, eyes desperately tracing his features, tacking together sentences that could explain why he had needed to kill Flash himself, why she hadn't been able to do it. She wound up with, "you came."

He took a step back in a blur of gold lightning and the shining bit of hope she had splintered across the floor like one of the icy cities she would never make again. Their gazes locked, and she saw dawning comprehension rising in Flash's face, and wondered what he was seeing in hers.

After a second, Flash broke the connection and whipped out of there in a trail of gold, leaving her to sink to the floor of her cell, mind whirling. It kept catching on Flash's face, like a loose thread, and then trailing back to Zoom before she forced herself to think about why she was here. The fact that Flash had Zoom's face, or Zoom had Flash's, changed nothing.

But she still kept coming back to that first moment when he had stopped the disguising gesture and she believed, hoped so desperately, that it was Zoom, and that led to all the times she had seen him without his mask on, looping around in an endless cycle.

The first time she'd seen Zoom without his mask was also the day he'd given her the name Killer Frost.

It was also, now that she thought about it, the first day she had killed someone. She had been so young then, so naive and still so confused about everything. Zoom was looking away, and didn't see the officer sneaking up behind him, didn't see her raising the gun, was unaware of the danger.

She had reacted without thinking then. She hadn't meant to do it, but when she flung out a hand, yelling Zoom's name, ice had shot out. It sharpened in midair, and by the time it had reached the officer, it was sharper than any natural icicle could ever be.

The officer staggered, the gun falling from her grasp as she clutched at the ice suddenly protruding from her chest. She had enough time to look up before she fell to her knees, the edges of the crystal-clear projection turning crimson and melting under the heat of the blood rushing out from the wound. She had been frozen there, hand still outstretched, as Zoom appeared next to her, sweeping her up without stopping. The last she had seen of the injured officer, someone in civilian clothes, gun in hand and badge flashing at his hip, was running to her, but then Zoom whipped them out of sight. He didn't stop until they were standing back in his lab, and even then he set her back on her feet and moved to set down the bag of things he had taken on the workbench.

She remembered being unable to stop staring at her hands while he moved around, setting things up the way he wanted them.

"You had my back," Zoom had commented, "I had underestimated your loyalty."

She hadn't meant to do it. She opened her mouth to tell him that, that the act had been a mistake, a fluke, but the words froze in her throat as surely as if she had used her powers on them to stick them there. Zoom huffed, appearing in front of her in a flicker of blue. "Look at me," he ordered.

She was distraught enough she didn't notice at first that he had stopped speaking in the double-tone, but then he slid a hand under her chin and pulled her face up so she had no choice but to look at him. Before that moment, she had imagined a dozen reasons he wore the mask. She'd thought that maybe the explosion that had made him what he was had also disfigured him in some way, or maybe he was someone that the police would recognize, some public official who needed to remain anonymous, or maybe he couldn't control his powers without the suit completely covering him.

But none of those things were true. She knew all the public officials, and she didn't recognize him. He looked like anyone she might have passed on the street, he wasn't disfigured. If anything, he was handsome. There had been little time to take him in though, because then he had kissed her, backing her up against the nearest wall to get a better angle.

"My killer," he had breathed into her ear, so warm it made her shudder and pull him closer to her. There had been a pause where he traced patterns onto her skin, chasing the frost that bloomed, "Killer Frost." After that, he had called her Killer Frost in public, Killer in private, and she had stopped sleeping in her own room.

She climbed into the bed in her cell and pulled the covers up around herself, cold despite the cuffs. She would give anything for that now, to be able to curl into Zoom and be warm, not this artificial, constant warmth that was forced on her by Cisco's invention, but the kind that Zoom shed like a duck shed water, the excess speed burning off into heat. If she was lucky, maybe she would dream and be back where she belonged, the way she was supposed to be, with ice in her blood and frost at the tips of her fingers.

It took a long time to fall asleep, and she had no idea how long she stayed that way, but Flash was standing outside her cell again when she woke up. She sat up, the blanket slipping down, and swung her legs over to set her feet on the floor and they watched each other without saying a word.

"Why did you show me?" Killer Frost asked finally, "your face, I mean."

"I thought it would make it harder for you to kill me," Flash replied, "if I was more than just a costume and some speed, if you could put even part of a face to me. I didn't think I had your-" there were words in the minute break there, but he seemed just as lost for them as she was, "had Zoom's face," he corrected finally.

In a way, it made sense. If Zoom in her universe had superspeed, other versions of him could have the same gift after the accelerator exploded.

But in another way, there was only one Zoom, and it felt wrong that someone else was running around with his face and his gift, even if it was in another universe. "Neither did I," Killer Frost told him.

"Could you kill me now?" he sounded hopeful.

She sat up a little straighter as a plan formed itself in her head. She paused long enough to make it believable, then shook her head, slowly, indecisively. "I don't know," she said, tentative, exactly like she couldn't believe she was really saying this, "you look just like him. I-" She looked down, fixing her gaze on the floor.

It would never have worked on Zoom, but this was Flash. Without looking up, she knew it had worked as the door to her cell swooshed open, and she heard footsteps come closer. She forced herself to remain still as he came to her, until he was standing in front of her, trusting that the fact he wore Zoom's face would somehow save him.

Then he knelt in front of her, taking her wrists, the cuffs that kept her powerless, in his hands. She couldn't even feel how warm he was, the same warm Zoom was, with the blocks on. "I'm sorry," he said, "about these. We didn't know what else to do."

Then she lunged. She hadn't realized how much she had come to depend on her powers until she suddenly didn't have them, and the attack was utterly graceless. He wasn't expecting the motion, and even the fastest man in this universe could be caught off guard, and they tumbled across the floor, out of the cell as she tried to get her hands around his throat and he tried to ward her off. He couldn't escape as long as he couldn't run, so as long as she kept him down, he couldn't get away.

He seemed unwilling to fight her at full strength, and she used that against him, pinning him down and grappling with him as he tried to ward her off.

She wasn't sure how he did it, but suddenly they were moving, the world blurring past as he careened down a hallway, crashing toward a wall. At the last second, when she was nearly convinced he was just going to smash her into it to get rid of her, he turned, grazing the surface and skidding through a door that flung open under their joint momentum. This, it turned out, was a custodial closet, and she went tumbling through the sudden mess, still unwilling to let go of the tenuous hold she had on him.

Her questing fingers found something hard and she smashed it across her body into his head as hard as she could. He tripped backward, falling to the floor with his feet tangled in a mop as she finally let go and scrambled to her feet. She raised the object again and he ripped his mask back.

It was exactly Zoom's face. Until that instant, she had held onto the faint glimmer of hope that maybe he just looked like Zoom in the parts of his face that weren't covered by the mask, but there was no mistaking him. "Go on," he said, "finish it. I'm a murderer too."

And she couldn't. She couldn't even muster up enough to be angry that he was wearing Zoom's face, she just couldn't. Not when he sounded as bitter as she had once felt, before Zoom told her there was no reason to be that. There was no way to fake that, not without having lived it.

She turned and fled blindly through the door still hanging mostly open, tearing through the halls without really caring where she was going. Anywhere was better than there, with a man wearing Zoom's face saying he deserved to die with absolute conviction in his eyes. She turned another corner and found herself in a large room.

But there, in the middle of the room, about seven feet up, not far from a stack of metal boxes, was the tumbling, rolling motion of a breech between the universes. Desperation made her hands tremble as she hauled herself up the stack, expecting any moment for Flash to come into the room and spirit her away, back to the cell where she would live out the rest of her days, cut off from everything she held dear.

It was a jump, but she was desperate now. She didn't want to face Zoom like this, without succeeding, but she had no choice, no options left but to go through the breech. She couldn't stay here and let them strip away all her powers, take away everything she was.

Even as she set a foot on the last box and pushed herself off, she saw a flash of gold. The Flash appeared where she had been standing an instant ago, watching her with a helpless expression on his face.

It was odd, she thought, as the breech swallowed her up, but he had never tried to kill her. Even when she had stood a good chance of ending his life, he hadn't really been fighting her, hadn't tried to kill her in return. Zoom would have killed anyone who tried to do the same to him, but Flash hadn't.

Then the breech took her away.

* * *

 **Extra Scene**

Barry sat forward, struggling with the mop that had somehow managed to knot itself around his legs while Killer Frost was trying to kill him. She had not been half-hearted about it either, his throat was already aching where she had wrapped her fingers around it and his head was starting to throb from where she had smashed a bottle of cleaner into his skull. He was going to have spectacular colors of bruises.

The door burst open the rest of the way and Joe's frame filled the entrance. "What happened?" he demanded.

"Killer Frost," Barry replied, tugging on a particularly vicious strand of mop, "I thought I was making progress with her, I went into her cell, and she attacked me."

Joe looked over his shoulder as though the errant meta would be behind him. "And why did she stop?" he pressed.

"She ran off when I told her she should kill me," said the speedster, as casually as he could, dumping the mop onto the floor of the closet and looking for a way to stand up.

"How did you know that would make her stop?" the detective asked.

Barry, finally free of cleaning supplies, pulled himself to his feet and looked Joe in the eye. "I didn't," he said, then ducked under the man's arm and sped off to find their escapee.

* * *

 **Most of this is from Killer Frost's view, but occasionally there are scenes that wanted to be told, that add to the tale, and couldn't be from her view, so they'll pop up as an "Extra Scene" at the bottom. Read them or ignore them as it suits you.**

 **If anyone is interested, I'll be putting a little more detail about the universes Killer Frost visits down here, as she leaves each one, exactly what happened to make them diverge from the Earth-1 we know. Again, if you don't care, feel free to skip it, but it's here if you want it.**

This was a world where Barry came back from saying goodbye to his mom in time to prevent Eobard from going through the portal, and Eobard threatened his friends and family. Faced with a choice between himself and everyone he loves dying and doing something about it, Barry chose to snap Eobard's neck, so Eddie didn't die and there was no singularity.

 **Watch out for the next chapter soon! Happy holidays.**


	3. Pictures of Strangers

The trip was even rougher this time.

It felt like she was being rolled through a tube full of boulders and she could do nothing but squeeze her eyes tightly shut, blocking out the endlessly undulating liquid blue walls and wait for it to be over. And then suddenly it was, and she was crashing hard to the same tile floor she had just left, landing into a stack of the same metal boxes she had just jumped off and sending them flying across the room.

A quick glance around showed the room was arranged different from the one she had just left, she had traveled through universes again. She certainly felt battered enough to have crossed into some other world.

The cuffs had stayed with her, still weighing down her arms and giving off the ever-present heat, and she started looking around for something to get them off with. Something she could make into a lock pick would be best, but she would take some sort of bolt cutters or blunt object if that failed.

She found a box of paper clips and sat down on one of the overturned boxes to try and pick the cuffs off, but her hands were shaking badly enough that she couldn't get it work. She fiddled around with the clips for a while, but only really succeeded in leaving a lot of scratches on the metal.

A hand landed on her shoulder, and without even looking she knew who it was. Only a speedster generated that crackle of electricity upon arrival, and Zoom was the only speedster in this universe. "They took my gift," she held up her wrists, voice thick with tears she refused to let fall, "I couldn't, I'm sorry."

He crouched down next to her, and she was starting to become concerned. Zoom was never gentle for this long unless he was very pleased or very angry and saving the retribution for later. And she couldn't have pleased him. "It's alright," he said, "you're safe now."

Killer Frost looked up from the cuffs that she had only managed to scratch, because he wasn't using the double-tone that he always had outside his rooms, no matter how secluded the location. And this was STAR Labs, he shouldn't even be here, not when Harrison Wells would do anything to catch him.

It wasn't Zoom, and yet it was. The man in front of her was dressed in red, but the half-mask over his face didn't stop her from recognizing him. She would know that face anywhere. He was gaping right back at her, and then, so hesitantly, as though he was afraid she would break: "Caitlin?"

She stared back, not quite sure what to make of that. She had been Caitlin once, a lifetime ago, but no one knew that name anymore, Zoom never used it and the police, who were almost the only other people to address her, didn't bother using names when they called for her to put her hands up and surrender peacefully.

"Caitlin," Flash repeated, and then he scooped her up, an arm under her knees and the other curved around her back, and they were moving.

"What?" Cisco jumped when Flash skidded to a halt in what looked like a lab, if the equipment she could see through the glass wall was anything to judge by, "dude, what's happening?"

Flash was making a beeline for a medical table as he spoke. "It's Caitlin," he said, laying her down on it. She fastened a hand around her arm when he started to move back, and he stayed close without a hint of hesitation. His free hand came up to sweep his mask off, revealing Zoom's familiar features, though she had never seen them arranged into such a worried expression before.

"I just got off the phone with Caitlin, like five minutes ago," Cisco replied, "she's picking up Chinese."

"Then explain this," Flash stepped sideways a little in clear invitation, and Cisco moved up to join him at her bedside.

"Whoa," the engineer said, "that's freaky."

"Can you get these off me?" Killer Frost asked him, holding out the arm not latched onto Flash.

He took the appendage and examined the cuff carefully. "I don't know," he said, "this is serious. I think," he left the sentence hanging and scampered across the lab, returning with a magnifying glass. "Yeah, something's wired to the locks," he said, "opening them without the key could-" he reeled back again, stopping several feet away, pointing back at the cuff. "Is that a bomb? Are we all going to explode?"

"Just get them off me," she said.

"Okay, one scan coming right up," Cisco turned on his heel and headed to a corner of the lab.

"It's going to be okay," Flash soothed her, "we'll get these off you. I won't let anything happen to you."

"You promise?" she questioned him, as Cisco wheeled over a complicated-looking machine hooked up to several sensors, and the grip on her hand tightened.

"Yes," said the speedster, "I promise."

Cisco hooked several of the leads to her arms, then ran what looked like an airport metal detector over the cuffs. Several button clicks and a great deal of typing later, an image of the cuffs and her arms popped up on screen.

"Okay," Cisco pointed to the scan, where the cuffs were rotating slowly, showing an internal network of wires, hooked up to several small clusters of circuits, "the good news is that this is not a bomb."

"And the bad news?" Flash prompted.

"The bad news is whoever put this on her did not want it to come off," replied the engineer, "it's not a bomb now, but I cut the wrong wire and it turns into one. It looks like it was designed to pump out some serious heat, and if I cut the release of that, it's an inferno in a bottle."

Killer Frost pulled her hands into her chest, suddenly acutely aware of the scratches on the locks. How close had she come to blowing herself up? And how badly had the other Cisco wanted to keep her powerless, that these couldn't come off? "Can you get them off?" she asked him.

"Given some time, yeah," he agreed, "just let me spend some time with the specs and I'll get these babies singing to whatever tune I want them to play."

She sat up, sliding sideways to swing her legs over the side. Flash had zipped off to look at something on the screen, though he was still hovering at the edges of the room. She didn't mind that. If he didn't move at superspeed, she could almost pretend he was Zoom, and if he stayed close, it would be easy to kill him once she had her powers returned to her.

"So what now?" she asked.

A streak of red and gold crossed the room past her, stopping at an assortment of shining medical tools laid out on a table, then returned to lay several of them on the edge of her bed.

"Hold out your hand," he said and she did. He took her wrist, turning her arm over, and swabbed the inside of her arm with something. There was a sting in the area as he put a needle in and she forced herself not to flinch. "Sorry," he said, then gave a quiet laugh. "Reminds me of when I woke up and the first thing you wanted was a blood sample."

She nodded absently, watching the vial fill quickly with her blood, and he bandaged the area, instructing her to apply pressure.

Once the vial of red liquid was safely sitting on the table, he swept her up again, the same way he had carried her before, and the room rushed by as he crossed into another.

It was barely two heartbeats later before he laid her down, so gently, as though she was something precious and fragile. She only realized that this wasn't another medical bed when he was standing back up. "I'm sorry," he said, and then he was on the other side of a door that was closed on her.

"Umm, dude?" Cisco's voice rose in a question from somewhere out of sight, growing clearer as she moved toward the door, "What are you doing?"

"She's not Caitlin," Flash's shoulders had dropped, his voice defeated, "it just looks like her."

Killer Frost pounded on the door, desperation rising as the memory of the cell resurfaced. She forced it down, taking one breath, then another. Desperation would not help her here. "Flash," she said, spreading her fingers on the glass, "you promised to get these off me."

He mirrored the gesture. "We'll do that once we know who you are."

And then he moved off to do something with the vial of blood he had taken, leaving her standing there, still powerless, trading one cage for a larger one.

She wound up sitting on the floor with her back to the door and her legs stretched out in front of her, half-dozing. If nothing else, being locked in the cell for however long it had been had taught her how to wait.

"I was looking at the cuffs that were on her," Cisco's voice said, pulling her back from where she had been balanced at the brink of sleep, "and they were exactly what I would have made."

"So someone with engineering abilities tried to take away her powers," said a female voice.

"That's the thing though," Cisco interjected, "it wasn't just 'someone good', or 'someone with engineering skills', it was me. I know how I wire things, and that was my wiring. I made those cuffs."

"What are you saying?" that was Flash.

"I'm saying I made it, but I know this me didn't," said the engineer.

"This you?" the woman echoed.

"Think about it," Cisco urged, "she looks exactly like you, Caitlin, well, except for the hair, and her DNA is a perfect match. Unless you have an identical twin hidden away somewhere, or the particle accelerator exploding made another copy of you, she has to be from another universe."

"It does seem to fit," Flash put in, "When I found her, she acted like she was expected. She was talking about how she hadn't been able to do something, it was like she was reporting back to someone."

"Hold on," said the woman, Caitlin, Cisco had said her name was, and Cisco shushed her as Killer Frost shifted against the door. When Caitlin continued, it was at a volume that she had to crane to hear, "we're talking about another universe. I know we've seen some crazy things, but other universes?"

"Hey," that was Cisco again, and from the tone she imagined him with his hands up, "personally, I think time travel ranks above other universes on the craziness scale."

"What are we going to do about her?" that was the woman, "she can't just stay in the treadmill room, but we've seen no reason to put her in the pipeline."

"Someone put those cuffs on her for a reason, and we still don't know what that is," Cisco said, "as far as I can tell, the amount of heat these babies are generating is enough to cook your dinner on, but she's okay, so we can cross normal human off the list of things she is."

"We can't let her out," that was Flash, "not until we know who she is and why she's here. But we also can't put her in the pipeline without a reason."

"How about freaky appearing skills?" volunteered Cisco, "if she can teleport like Peek-a-boo and change like Everyman, she could be stealing their powers."

"It could be Everyman all over again," Caitlin added.

"Have you tried asking her?" this was a new voice, female, but different from the one who had spoken thus far. There was a long and guilty pause on the other side of the door, then someone sighed. "I'll go do it."

Another new voice spoke up, this one male. "No, I'll go," he volunteered.

"I'm pregnant, Eddie," said the woman, "not made of glass. It's still my job to ask questions."

"But we still don't know what her powers are," Flash jumped in, "and we don't know how it could affect the baby."

The newcomer sighed. "Then we ask," it wasn't a question, and she scooted just far enough away from the door that she didn't fall when it opened a few seconds later.

A blonde man with a badge clipped to his hip let himself into the room, and Killer Frost stared up at him as he settled himself on the edge of the treadmill. He looked familiar, and it wasn't difficult to remember where she had seen him before, in addition to doing her interrogation the first day, he had done several lunch runs in the other universe. "Thawne," she greeted.

"Yes," he said, sounding surprised, "I am. Who are you?"

"My name is Killer Frost," she told him.

"Hello Miss Frost," he said, "Do you mind if I ask you a few questions?"

This was different from the usual approach police took, more friendly than what she was accustomed to. She eyed him suspiciously, but nodded her consent.

Thawne leaned forward, elbows on his knees. "How did you get into STAR Labs?" he asked.

"From another universe," she said, and she meant the words to be a snap but they sounded more tired.

His eyebrows went up a fraction at the words, but other than that he showed no signs of surprise. He opened his mouth once, closed it, opened it again, and looked no less like a dying fish for the pause. "Another-?" he cast a desperate glance at the door, but whatever reinforcements he was hoping for where nowhere to be found and he returned his attention to her.

"Is that where you got the cuffs?" he asked, tone gentling to one he might use on a frightened animal, or a trauma victim.

"It is," she felt safe admitting that much, at least. "They're meant to keep me powerless," Killer Frost picked up a wrist and turned it over. For having been banged against walls, traveled between universes, picked at, and having the possibility of turning into a bomb, they were in fairly good shape, "My captors in the last universe were frightened of me, of what I could do."

All technically true, but he would not arrive at the exact sequence of events she had been through. Another of Zoom's tricks, whenever possible, don't lie.

"What can you do?" Thawne asked, hands still hanging loose. He was starting to trust her. Good.

"I pull in heat from the things around me," she explained, "I can direct that to make ice, snow, and frost. I'd show you, but..." she trailed off, spreading both hands with a shrug.

"We'd have to get them off first," Thawne surmised, "one last question." She nodded, and he continued, "why did they lock you up?"

She hesitated before answering, sorting through the events of the last universe. The short answer was she'd tried to kill the Flash, but that answer would get her thrown back in the pipeline with no hope of escaping again. They were frightened was also correct, but she had a feeling he wanted more than that for an answer. Zoom she refused to reveal, when he came, he wouldn't want them to be prepared for him.

"I-" she fixed her gaze to her hands, clenched together in her lap, "I nearly killed people before I got my powers under control." Which was true in her first universe, before Zoom had taken her under his wing. "I did kill a few trying to control them."

"But you have them under control?" he pried.

She nodded. There was silence from the detective, and Killer Frost hardly dared to move. If he didn't like her answer, there was nothing she could do to stop them from bundling her up and flinging her back into the pipeline. She was outnumbered, and without her powers she didn't stand a chance.

He stood, took a few steps closer, and then a hand came down on her shoulder and squeezed. She dared a look up, and found . "We'll get those off you," he said, and offered a hand up.

She turned her lips up into something resembling a smile and let him pull her to her feet, then followed him into the main room.

"This is Killer Frost," Thawne said when they cleared the doorway, "she has ice powers."

"Hey," Cisco greeted, spinning around in his chair and not even trying to hide the fact he'd been listening in, "Sorry about the whole, locked in a random room thing. We haven't exactly had the best track record with people who have other people's faces. First Everyman, then Dr. Wells."

"Harrison Wells?" she asked, confused now.

Cisco's expression went dark for a second. "You know him?"

She nodded, still waiting for the other shoe to drop. "He runs STAR Labs in my universe. How does he have someone else's face?"

"Harrison Wells in our universe was actually a speedster from the future named Eobard Thawne," that was the Flash, leaning against on of the tables. He had changed out of the red costume and into street clothes, but she recognized the face and the voice, "he called himself Reverse-Flash."

The name was so ludicrously unoriginal she couldn't stop the disbelieving look. "Reverse-Flash?" At least Zoom had been creative.

Cisco snorted. "And good riddance to him, he's serving time in Iron Heights for multiple counts of murder with his shiny new speed suppressors. Last I heard the other inmates don't like him very much. Serves him right."

There was a little more venom and bitterness there than was strictly necessary, but she didn't press the question, as the hugely pregnant woman who had been sitting in the other desk chair stood up and waddled toward her. She spared the detective a brilliantly sweet smile when he slipped an arm around her waist, the gesture familiar and practiced.

"Iris West-Thawne," the woman said, extending a hand.

She hesitated an instant, the habit of touching no one but Zoom unless she wished to harm them kicking in, but then she took the woman's hand. "Killer Frost," she replied.

"You've met my husband Eddie," Iris continued, "this is Barry Allen" she gestured to the Flash, "Caitlin Snow went to check one of the test results, and this is Cisco Ramon."

"So uh, Killer Frost," Cisco swiveled around once in the chair, leveling a pen at her for emphasis when he faced her again. "Is that the name you had before your powers, or is it open for suggestions? 'Cause I'm not seeing anybody giving their child Killer as a first name."

"That is my name," she shot back, "and I'm not changing it."

Cisco deflated and spun back to face forward. His head snapped up, and he glanced over his shoulder at her, then back to the brunette woman over by the medical equipment, "Oh that is weird," he told them.

"What?" the woman turned around, and whatever else she had been going to say stopped dead as she and Killer Frost stared at each other. She recognized Caitlin from the voice that had been talking earlier, but the woman had exactly her face. The hair and the eyes were both brown, but before her powers kicked in and her eyes iced over blue, hers had been the same way. It was like looking through a window into the past.

"Oh," said the woman, "I see now. Maybe I shouldn't touch her. Just in case."

"Probably a good idea," Cisco contributed, "that's generally when universe ending paradoxes result in all the movies."

"Or when you touch a version of yourself from a different point in your time stream," Flash added.

"Speaking of other universes," Thawne cut in quickly, before the conversation could completely degenerate, "how did you get here?"

She had to do a quick review of what had happened to make her wind up here, to check what she could and couldn't tell them. "I'm not sure exactly," she said finally, slightly hesitant, "I came through a breech between the universes, but I don't know where they originated or what caused them or even how many there are."

"Wait a second," Caitlin said, comprehending something, "that means the breech is here, at STAR. That's how you got past the new security."

Killer Frost nodded. Flash pushed himself upright from where he had been leaning against the desk and vanished past her in a stream of lightning. He returned seconds later, skidding to a halt next to her. "Found it," he announced, "same room she was in."

"Across the hall from the movie room?" Cisco asked.

It was so ingrained in her to reach out for Zoom, to ward the chill off, that she didn't realize she had taken the step sideways, starting to lean against Flash until the jolt when she couldn't feel his heat went through her like hitting a physical wall. She stepped backward immediately, and earned a flicker of a confused look from the speedster before he brushed it off.

"Speaking of movies," Barry changed the subject, "since no one is destroying the city tonight-"

"Star Wars," the engineer said instantly, "the new one comes out soon."

"But I almost died yesterday and-" the speedster began, and Cisco interrupted.

"Not to be insensitive dude, but you almost die at least once a week. It is my turn to pick and I pick Star Wars."

Caitlin was nodding along with a sympathetic expression, and Killer Frost was watching them go back and forth like it was a tennis match, the scene bizarrely normal. She didn't realize she was starting to smile, just a hint of one, until she felt her facial muscles move.

Barry gave up, and vanished in a blur of gold. He reappeared seconds later with a stack of DVD cases that he set on the desk.

"No, you don't watch one," Cisco said, pulling the case out of the stack and shoving it into a random desk drawer, "you watch four-five, then two-three, then you end on six, so the originals become a frame tale for the prequels and you don't have the sequences where Darth Vader is a weirdly adorable little kid."

"Iris?" Barry pleaded, turning around for reinforcement.

The detective's wife raised an eyebrow, the expression at odds with the amused little smile on her face, and heaved herself back to her feet where she'd sat down at one of the desk chairs. "We're going home and my only plans are a bowl of ice cream and going to bed. I'm sleeping for two and she's tired. You're on your own for this one, Bear."

"Killer?" he turned to her, and she couldn't stop the flinch at the name, mind racing back to Zoom and how disappointed he was going to be when he found out she'd left the last one alive. "Hey," he appeared in front of her, wrapped her hands up in his, "What's wrong?"

She froze, as surely as anyone she'd ever used her gift on, gaze fixed on her hands, swallowed up by his. Zoom would never have done anything like that, probably wouldn't have noticed the involuntary reaction. But then, she had never flinched with Zoom, had never disappointed him like this before.

She heard muffled voices and a few small clattering noises as Cisco rooted through the stack.

"We'll be in the movie room," Caitlin said quietly, and footsteps receded down the hall, splitting apart as Iris and Thawne went a different direction.

"He called me Killer," she managed out after a moment. The words felt too close to a betrayal to feel right in her mouth.

"Who?" Barry asked, "your captor?"

It was easy to nod. The other Barry had never called her by any name, but he and Zoom were versions of the same person.

"It's okay," he soothed, "you're safe now, They can't get you. They won't get you."

She turned her hands over in his grasp, looking again at the keyholes on the cuffs. She still felt like she was submerged in warm bathwater, and the sensation was cloying. "I can't defend myself without my gift," she said, and wanted to reel the words back in the second they escaped. She sounded weak, and Zoom would have-

The thought derailed as the speedster spoke again. "I'll protect you until you have your powers back," he promised, green eyes sincere when she looked up to meet them, "And you will get them back."

Inconceivable as it was, she believed him. Zoom would tear him to shreds, but she really believed he would go down fighting. For her.

It took her another moment to regain her composure, but he kept her hand as he lead the way to the movie room, where Cisco and Caitlin had already gotten everything set up. The logo was frozen, projected onto a blank wall, someone had made popcorn and the half of the battered couch that was definitely not STAR Labs issue was waiting for them. She settled between Cisco and Barry, Caitlin on the engineer's other side, and Cisco told the movie to play.

The fanfare rang out, two droids escaped, and she was engrossed.

She fell asleep somewhere around the time Luke and Han were receiving medals, the relief of not being in a cell making her more exhausted than she would have been otherwise. When she woke up again, it was morning, she had the couch to herself and someone had draped a blanket over her.

Leaving the blanket behind, she started wandering. If STAR Labs was laid out the same in every universe, it would be an excellent idea to be able to navigate through here. When she found her way back to the central room, both Barry and the Flash suit were nowhere to be seen and Cisco was seated at the computer, watching something on the screen.

"Oh good, you're awake," Cisco called out when she stepped into the room, "can you watch that half of the cameras and tell Barry if someone sneaks up behind him?"

Her last attempt to kill the Flash without having the use of her powers had gone so _spectacularly_ well, she thought even Zoom would understand if she didn't kill this one yet, not until she had her gift back.

Until then, she should really get them to trust her. She took the chair Cisco indicated, and started helping Flash save the city.

It took Cisco a month to figure out how to get the cuffs off her without blowing them all to kingdom come. By the end of that time, she had seen all the Star Wars movies, the entire Back to the Future trilogy, most of the Marvel Cinematic Universe, the lab had nearly been blown up three times (twice by a metahuman, once by Cisco), they'd saved the city from nefarious meta-humans four times, Iris had had her baby and named Barry godfather, and Cisco had wound up simply recreating the key by making a perfect replica of the cuffs.

And she knew them now. She knew Barry had a heroic streak a mile wide and Caitlin always scolded him for taking dangerous risks, and he would nod and say he wouldn't, until the next time. She knew Cisco kept a stash of candy in his desk and Barry was forever buying more because he'd eaten it and felt bad about it. She knew Barry used to be in love with Iris, still went out to lunch with her every Friday, but Iris was so head-over-heels for Eddie it was impossible to imagine the pair not together. And she knew every time the cuffs got to her, made her feel like she was suffocating, Barry was there to get her through it.

It was almost like vacation, no buildings to break into, no police to run from, no moves in the middle of the night where Zoom could erase all traces they'd been there in sixty seconds; just the occasional meta-human.

But Cisco came running into the lab one Tuesday morning, hair sticking in all directions like he'd just been electrocuted, waving a bit of metal over his head. "I got it!" the engineer announced, "I can unlock the cuffs." And her heart sank a little, she wanted these off, but she didn't want this to end either.

She had started to extend a hand, still desperately eager to get them off and get her gift back, but no sooner had Cisco taken the offered arm when she reached out and stopped him. "Let Barry do it," she said.

The speedster's face reflected the surprise on the engineer's, and she carried on. "I don't know how my powers will react when you undo the cuffs," she explained, "he stands the best chance of getting out safely if they do act up."

Cisco yielded to her logic, explained what Barry had to do, surrendered the key, and they went to the breech room. The key clicked in first one, then the other, and he pulled them off at the same time and let them fall to the floor with twin clangs. "How do you feel?" he asked.

To her surprise, she didn't feel much different than she had a moment ago. She had been expecting to feel a rush of cold, or maybe an explosion of ice, something more dramatic than just the cuffs coming off. Holding up a hand, she called for ice.

Her powers answered, and for the first time in far too long, snowflakes formed at her fingertips, growing thicker by the second until she had a tiny blizzard swarming around her hand and a pile of snow accumulating at her feet. Killer Frost turned to him, really smiling for the first time since before Zoom had set her in an alleyway, and started to reach for him. Halfway there, she stopped, hand suspended as she caught up with that train of thought. She was finally capable of doing what she had been sent here to do, to leave him a frozen corpse on the floor.

He bridged the gap himself, reaching for her, trusting and open. "Kil?" It would be so easy to step into the touch, to slip one of her icicles into his chest. He would never see it coming. This was why she was here, the mission Zoom had given her.

But she had watched his back while they saved the city, she had seen his face when he held his goddaughter for the first time, he had given her a new nickname when she couldn't stand the old one, and she had fallen asleep on his shoulder that first night here. She twisted away from the touch, and the breech writhed overhead. She couldn't kill him, so she couldn't stay here.

She looked up, meeting his eyes, confusion and hurt written across his face. "I'm sorry," she breathed, "I don't want to kill you." And threw out a handful of ice, throwing him backward. Without waiting to see what would happen, she leapt into the air, creating ice under her feet.

The breech opened above her, and through vision turning blue, she found Flash slowly climbing to his feet.

She didn't know whether the pang that went through her was relief or regret, but there was no time to think about it as she smashed into something and the breech whisked her away.

* * *

 **Thanks everybody who's reading, I appreciate all of you.** **Hope you enjoyed the chapter. Here is the detail about the universe.**

This is a world where Iris accidentally got pregnant while Barry was in the coma, and Eddie, being the responsible gentleman in love with her that he is, immediately asked her to marry him. She said yes, on the condition that she wanted her father to walk her down the aisle and her best friend to stand up next to her on her wedding day. She insisted they knock Reverse-Flash unconscious for the entire time-travel incident and no one was willing to argue with the hormonal pregnant lady.

 **The order Cisco suggested for the Star Wars movies is called machete order, and there's more details and arguments and counter-arguments online if you want to know more. Happy holidays, next chapter should be out in a few days.**


	4. Gaze of the Abyss

This time, when she was dumped out of the breech, three flat grey walls greeted her, and she caught herself on a desk, right next to a man who had been on the phone until a meta-human from another universe materialized out of thin air.

Killer Frost bent down, picked up the phone where it had fallen, and placed it back into his unresponsive fingers. "Have a nice day," she said when he showed no sign of remembering how to speak anytime soon, and walked herself out of the building. To her surprise, the building she had just walked out of was out several blocks away from STAR Labs. The breech must have shifted between universes, or the universes weren't aligned exactly. Cisco would probably have had a better explanation, but Killer Frost put it out of her mind. This time, this universe, she had to kill Flash, and quickly, before something interfered.

It was raining, just hard enough that people were hurrying to get back indoors with their heads down and didn't notice that she left a trail of tiny pebbles of ice in her wake. Even with the obscuring veil of the weather, STAR Labs was easy to make out, and she made a beeline for it. The STAR labs protocols all recognized her as Dr. Caitlin Snow, so getting in was as easy as finding a door that still opened.

There was no one in the lab when she let herself in, so she sat down and settled in to wait, crunching the coating of frost that had developed on her from the raindrops. Someday, she was going to find a universe where Caitlin Snow didn't exist, or didn't work at STAR Labs, but until that day, this was a convenient shortcut to finding the Flash, and much safer for her than storming the police station.

She didn't have to wait long. Flash skidded to a halt in front of the desk, going from running to typing on the computer in one seamless movement.

"I told you not to be here," Barry said. He hadn't even looked at her yet, or maybe he had and it had just been too quick for her to notice.

"And yet here I am," Killer Frost returned, lounging back in her chair.

He glanced over, this time slowly enough for her to notice. There was a blur of lightning and a rush of wind and then she was suddenly sitting outside in the rain again, with Flash disappearing back into the building.

She gaped, angry now, and stormed back into the building, leaving more trails of water in her wake. He was still typing when she reentered the room, only stopping when she cleared her throat.

"I don't care," he told the computer screen shortly, not bothering to turn around, "I'm going to catch him, and then I'm going to kill him."

"No you're not," she retorted.

He sighed, and when he put his hands on her this time, to repeat the same maneuver he had just done, Killer Frost froze the puddle of water at their feet, the ice climbing him to secure him to the floor. He looked down, eyes wide with the shock of the sudden cold and the lack of mobility.

"Hello Flash," she said, "we weren't properly introduced. I'm Killer Frost."

"Caitlin? What are you doing?" he sounded more annoyed than anything, she was getting sick of them all confusing her for her doppelganger, and by the way he was holding himself, this one was already expecting some sort of backlash. She hadn't yet managed to kill a single one of the Flashes she had come across, but here, finally, was a Flash she could take out everything she was supposed to be doing onto and she had to take full advantage of that fact. She shoved down the thought of the last Barry she'd run across, she wasn't weak anymore and she had to take something back to Zoom. Failure was not an option.

With one hand pressed to his chest, both for balance and to establish another point of contact, she craned up and stole a kiss, and with that, a bit of the heat coursing through him.

She had done this before, kissed someone to freeze them. There were scientific, biological reasons why it was among the fastest way to steal the heat out of a body, but she found herself lingering for reasons that had nothing to do with temperature theft. Realizing this, she pulled away, stepping backward.

"Every time you get my name wrong, I will do that," she warned, carefully forcing her voice steady.

He was looking at her like she was some alien species he had never seen before.

"Nod if you understand me," she snapped.

Slowly, his head went up and then back down, eyes never leaving her face. It would seem she'd found a new and interesting way to silence the Flash.

"Now Barry Allen," she reached around him to pull out the desk chair he'd shoved aside, tugged it in front of him, and dropped into it, "we are going to have a talk."

"Cait-" before he had even finished the word, she was bounding up out of the chair to steal another kiss and bolt of heat. A normal human would have been dead by this point, but he was the Flash, and this was barely even approaching the beginning of what he could do.

"What did I say about my name?" she hovered in his space, barely a breath away, close enough that if she tipped her head just right she would kiss him once more.

"Killer Frost," Barry corrected himself, and she smiled at him, the slowly-spreading, desperately, obnoxiously in love one Iris had smiled at Detective Thawne in the last universe she had been in. Zoom would have approved, but it didn't sit right on her face, she could feel the edges of it slipping.

She glanced down at the flickers of static crawling up and down her legs. Someone less accustomed to a speedster wouldn't have noticed it, but she was, so she saw the flickers of motion as he tried to work his feet free of the ice block she had created.

"Oh no," she told him, and reinforced the ice with a thought, creeping it higher, over his knees now, then returned to her chair before she could do anything stupid, like kiss him again.

"Why are you here?" Barry asked. She didn't miss the continued attempts to escape the ice, but she ignored them.

"Who are you going to kill?" Killer Frost returned.

Confused green eyes darted up to catch hers. "You know-" he began.

"I am not your Caitlin," she said shortly, "explain it like I don't know."

He dropped his chin, fixing his gaze on the floor instead of her. "Harrison Wells," he admitted to the tile, "he's the Reverse-Flash."

"And you can't be here, Ca- Killer Frost," Flash's tone had turned pleading, "he'll kill you if he finds you helping me. I can't lose you too."

He was still trying to protect her, even knowing she wasn't Caitlin, even when she had him at her mercy, he was more worried about her than what was going to happen to him.

She shook away the thought that it was touching. She had to kill at least one, or Zoom would- she wasn't actually sure what Zoom would do, but she also didn't want to find out. "Flash," she stood up, circled him to stand at the other side, looking at what he had on the screens. It looked like a detection program. "I can protect myself, I don't-"

She felt it an instant before the computer beeped an alarm, the rush of static across her skin she had come to associate with the arrival of a speedster, and just had time to straighten up when there was another speedster in the room. He stopped with an arm around her abdomen, holding her still. The only thing missing was the knife at her throat, but then if she had learned anything with Zoom, it was that speedsters didn't need weapons.

"Hello Caitlin," the double-tone resonated through her, but it was wrong to be Zoom, or even any of the Flashes she had come across yet. The arm holding her tightly was clothed in black fabric, and the lightning sparking around him was not any version of Flash's gold or Zoom's blue, but bright red, "I thought I saw you come in here."

Barry wrenched ineffectively at the ice encasing his feet, though from where she was standing, she couldn't see it. "Let her go," he ordered, but the speedster behind her only laughed at the words.

"You knew what the penalty for helping him was," he said, low in her ear, and then louder to Flash, "I think you haven't learned your lesson yet." The hand not wrapped around her came up into her field of vision, vibrating rapidly, "You can't beat me Flash, we-"

Whatever else he was about to say, he didn't get to as Killer Frost blasted the appendage with ice. When he was shocked into stillness by that gesture, she turned around in his hold, grabbed the mask, and yanked him down to kiss, using the access to violently rip the heat from his body.

After a few seconds, she let go, wiping her mouth as he toppled to the floor. Now that she wasn't being held, she could see him properly. He wasn't dressed anything like Zoom or any Flash she'd seen so far, the costume yellow fading away into black rather than a single solid color.

"Don't get too close," Flash called out as she bent down. Heedless of the warning, she ripped back the mask on this speedster. Harrison Wells' face emerged, lax and unconscious from the temperature shock she'd just put him through. A normal human would be somewhere between dead and severe hypothermia had she done that to them in that extent, but he was a speedster, they were a little more resilient.

There was a crackling sound as ice shattered, and then Barry was at her side, pulling her backward, halfway across the room from Wells before he stopped. "What were you thinking?" he hissed.

"He threatened to kill me," she replied, pulling her arm out of his grasp.

Barry glanced down at her hands. "How did you do that?" he asked, "any of it. You didn't have powers last time I saw you."

"I do now," Killer Frost said. She could have frozen him again, but an idea was forming. Zoom would be pleased as long as she killed a speedster, and maybe, _maybe_ there was a way she didn't have to kill him, a way that would pass Zoom's approval, as long as she phrased it right. With that thought, she made her way back to Wells' side, crouching down next to him and starting to make bands of ice.

"This is Reverse-Flash?" she threw the comment over her shoulder, mostly focused on the chains she was making around his ankles, wrists, and waist, then added another across his neck for good measure. Barry and Cisco had given her a quick overview of Reverse-Flash, but she'd never actually seen him.

"He's the Reverse Flash," Barry confirmed, as she tested the chains. Each one was cold enough that it would feel sharp to the touch of anyone without her powers, "he killed my mom, and Cisco, and others we don't know about too."

She hand't known his mother, but she knew Cisco, from several universes now, and she hadn't realized how much she was looking forward to meeting another version of him until she learned that she couldn't. "I'm sorry," she said, and was only a little surprised to realize she meant it. Cisco had been, she wasn't sure if he would call her a friend in any universe she'd been in so far, but they had been friendly.

Zoom would have liked Cisco too, but for entirely different reasons. Zoom would see Cisco's skills, and if the speedster from her home universe could turn the Cisco there, it would be that much harder for the police to stop him- them, especially if Cisco developed metahuman powers as well. He seemed like the type who would have been affected. Perhaps if she found a version of Cisco who had powers, she would bring him with her, along with a count of how many speedsters she had killed, as a present for Zoom, and perhaps he wouldn't realize how many versions of Flash she had let live, perhaps he wouldn't care that she had let this one live. But that would also mean turning Cisco over to Zoom, and she wasn't sure she wanted to think about how she felt about that right now. There was a part of her that wanted Zoom to herself, and another part that didn't want Cisco under Zoom's control, but another that reminded her she should turn any information to Zoom.

She would tuck the thought away for now, to use as a last resort. There might not even be a Cisco in her home universe.

"So what do we do with him?" she asked, stroking each chain in turn. At her touch, they refined, becoming clear and hard and flawless. Just because something was practical didn't mean it couldn't also be beautiful, and she had gone without her gift long enough to cherish every time she got to use it now.

"Now," there was something harder the steel in Barry's voice, as cold as her ice, "we kill him."

Before she could reply to that, he was gone. That was good, if he wasn't here, she didn't even have to consider having to kill him, and went to get a scalpel from Caitlin's medical supplies.

Now that she knew it was Wells in the costume, she wanted to kiss him even less than she had when he was just a random speedster holding her hostage, so cut open the front of his costume, exposing his chest right above his heart. The thought crossed her mind sometimes that there was something symbolic in the fact that it was easiest to drain the heat out of someone when she had easy access to their heart, but the medical side of it was that all blood had to pass through the heart, and if it was being chilled as it went through, then it was the fastest way to freeze that person. A kiss was the same general principle, it gave her access to their respiratory system, where all blood had to pass through to be oxygenated

There was the familiar rush of wind and the crackle of static as Barry came to a halt, and she spared a glance over her shoulder at him before turning back to Wells. Then what she had seen caught up to her and she whipped back around.

Barry was standing there, a piece of machinery in his hands that looked rather ominously like a gun, glowing blue at the sides and making a softly whirring noise. "Get out of the way," he ordered.

"I caught him," she argued back, "he's mine first."

"Well Mr. Allen," Harrison, it seemed, had woken up while she was distracted, and wasting no time to start talking, "you finally caught me. So now what? Turn me over to the police, let the system that has failed you all these years take care of everything? Or-"

He never got to finish that sentence, because Killer Frost smacked her hand to the rip in his costume, directly over his heart, and leeched out enough heat for the shock of it to sting. "I know how Harrison Wells talks," she told him, "and that is not it. Close, but not it. Who are you?"

"You have changed, Caitlin," he started and she blasted him again, the chill harder this time.

"My name," he gasped the sentence, "is Eobard Thawne."

"You killed Cisco Ramon," Barry interjected from over her shoulder. When she flicked a glance at him, he had dropped the gun to point at the floor.

Eobard shrugged as best he could with the chains she had made. "He knew too much," was the explanation he offered, "Believe me, I did not enjoy killing him."

"And you killed Nora Allen," Flash continued.

The yellow-clad speedster laughed, the motion followed by a grimace as it jarred things that she had frozen. "I'm afraid I'm not going to make it that easy for you Mr. Allen," he said.

Killer Frost dug her fingers into his costume, and the shock of cold that followed was enough to burn. "Here is how it's going to work," she said, not letting up the pull from his system, "we will ask the questions, you will answer them. If you annoy me, I will turn your blood to ice, one appendage at a time. Cooperate, and I will kill you quickly. Please me, and I might release you to his mercy. Do you understand?"

He writhed under her fingers, mouth moving as he gasped for words, and she let go. "I... understand," he gasped out.

"Good," she smiled brightly, and moved sideways to sit cross-legged next to him, "So, what happened in this universe? The Harrison Wells where I am from is not a speedster."

"How do you know that?" she reached for the hand nearest to her, intent on starting with his thumb, and he started talking very fast, eyes fixed ahead where Flash was standing. "I came from the future to kill Barry Allen before he became the Flash, but I was stranded here without my speed. I engineered a car accident to kill the real Harrison Wells and took his face to speed up construction on the particle accelerator, to make the Flash and get home. I've been training Barry, getting him faster so he can open a wormhole through time that I can use to finally get home."

He tiled his head, craning against the chain encircling his neck, to look at her. "You can sympathize with that, can't you? Being stranded far from home?"

Her hesitation spoke volumes, and they both knew it.

"Why would I ever agree to that?" Barry snarled from behind her. The tone was so much closer to what she was used to hearing from Zoom than anything she had heard from Flash that she had to glance back quickly to make sure it was still the Barry from this universe.

Harrison made a breathy sound that could be an attempt at a laugh or a sound of pain. "Because you could use it to save your mother, to prevent everything that has happened. Think, you could have the life you always wanted, you father would never be in prisoner, you would have your friends back."

It was tempting, and it wasn't even for her. She turned slightly, to see what Barry made of the offer, and took her attention off Wells.

Had she not frozen him in place as securely as she had, that would have been the end. He lunged, not at Barry, but in her direction. The ice around his arms splintered and gave, and the one around his neck cracked, but the band around his torso groaned, but held, keeping her out of his reach, and Barry raised the glowing gun and fired.

It wasn't bullets like she was expecting, or anything fiery at all. A wave of cold blasted out from the end of the muzzle, and left ice in great patches on everything it touched, pinning him back down and making him resemble an ice sculpture more than a speedster. "That was for Cisco," Barry said, lowering the weapon again.

Killing her, she realized, would add another bargaining chip, make his wipe-the-clock plan sound less crazy and more inviting. It was the sort of thing Zoom would have approved of. Not that Zoom would kill her, specifically, Zoom wouldn't hurt her; but the principle was something he might use.

Reaching for the hand closest to her, she didn't start with a finger as she had intended, she froze his entire hand solid. He cried out, and she pulled her hand back, letting the ice stop at his wrist.

"Is he faster than you?" the question took her slightly by surprise, she hadn't intended to ask that, but she found herself waiting for the answer on pins and needles. If he was slower than Flash... she didn't know what she would do with the information, but he was still a speedster.

"He's never been fast enough to catch me," Wells answered, "not before today."

She didn't realize she'd been holding her breath until she let it out. Zoom had said to kill the Flash, but if this one was faster, he would do instead. She would have something to show Zoom, and she wouldn't have to kill Barry.

Unbidden, the image of the second universe's Flash came to mind, with the absolutely certainty that he deserved to die for whatever it was he had done. She was all-too familiar with that feeling, had experienced it first-hand.

When she killed Reverse-Flash, someone else wouldn't have to face a killer's eyes in the mirror.

She nodded, once, steeling herself and shoring up her determination. "Good," she told Wells, or Eobard, or whoever it was, and set both hands over the rip in his suit. She had never actually drained a speedster before, and she wasn't expecting it when he fought back, twisting and writhing against the bonds and her powers, but she held on, freezing faster than he could thaw. In the end, she won, if she could even call this winning, partly because he was chained down and unable to run away.

She felt the give when he froze through at last and ripped her hands free with a jerk, falling backward. She caught herself on her elbows and froze, eyes fixed on her handiwork.

There were two handprints on his chest, frozen black against the white of the frost creeping over everything else, and for a second she was back, staring at that officer, the first person she'd ever killed, in the moment before Zoom took her away.

She closed her eyes, took a deep breath against the sick feeling creeping up her throat, and forced the memory away. She had needed to kill him, the alternative was killing Flash, and this way she didn't have to do that. Taking another steadying breath, Killer Frost reached out and closed her fingers around the emblem on his chest, the red lightning bolt set against its black background, and tore it free. Sitting back, she caught Barry's stunned face in the corner of her vision.

"You killed him," breathed the speedster.

Killer Frost glanced up at him and found him with one hand on the desk, the glowing gun hanging loosely at his side. "Yes," she replied, standing up and brushing flecks of ice off her pants. She still couldn't quite look at him, picking off scraps of yellow fabric that had frozen to the edges of the emblem instead. There weren't more words necessary.

Zoom would have killed them both anyway, not caring which was faster, but Zoom was not here, she was, and this emblem finished the mission Zoom had given her. A few universes ago, she would have killed Flash too, just to please Zoom, but now she'd killed the fastest man in this universe, and that was enough.

She should go now, but Barry still hadn't moved, eyes fixed on Reverse-Flash, and she hesitated just before she reached the hallway. If their positions were reversed, he wouldn't have left her if she was like this. Zoom would, but Flash wouldn't, and this was Flash, she couldn't leave him like this, not when he had helped her so much in the last universe. She still owed him for that.

He kept his phone in the same place in this universe when he wore the Flash suit. He even had the same password, and it was a simple matter to text Caitlin to come to STAR Labs. Her doppelganger could get through to him. She almost texted Cisco too, had the message completely typed out, but before she sent it, she remembered: Cisco was dead here.

With that done, she replaced the phone and headed out of the cortex. Each minute she stayed was another minute Zoom could question why she hadn't killed Flash, and her reasons were running out.

Fingers wrapped around her wrist, and Flash pulled her back around to face him. "Who are you?" he demanded, slightly desperate, "Why do you look like Caitlin?"

She didn't consciously choose to do it, but she wrapped her free hand over his, the same way he had when the cuffs would overwhelm her. "My name is Killer Frost," she answered, as gently as she could manage, "and you wouldn't believe me if I told you why I look like your Caitlin." Carefully, she freed herself, and left him standing in the cortex with the body of his mother's murderer, not daring to look back. If she had, she might have gone back and explained everything, stayed to help with the aftermath and the heartbreak, and she had to go before Zoom came for her.

If Zoom even knew where she was now that she'd moved universes twice from where he'd left her. The thought was simultaneously ridiculous, horrifying, and comforting. Of course he knew where she was; but if he did, he knew exactly how badly she had failed and if he did, he would come take her home.

With no need to rush, she made stairs by creating taller and taller cubes, until she could climb to the level of the breech. She hesitated at the top and glanced down at the emblem in her hand again, this symbol that she had done something Zoom would be proud of her for.

She should feel happy, or proud, or even just relieved, but somehow, the thought didn't bring her the joy she had thought it would, that it once had, and she curled her fingers back around it, hiding it from view as much as possible.

This was a victory.

So why didn't it feel like one?

Hurriedly, she stepped into the breech, hoping the shock of traveling between universes would make it feel like it supposed to, but the question kept swirling around her head as the breech snatched her away, slamming her around and painting her vision blue.

* * *

 **Information about the universe:**

In this world, Barry didn't run fast enough when the tsunami was threatening the city to travel in time, though the vortex wall did work to keep the wave from destroying everything. So Cisco remained dead, but Wells was unmasked there and then.

 **My apologies to any biologists who may be reading this, the science of Killer Frost freezing people, like most comic book science, is only loosely grounded in fact. Have a great New Years and t** **hanks for reading, next chapter will be up soon.**


	5. Only Weakness

The breech was closer to the ground this time, she staggered out of it rather than fell, tripping for a few steps until she caught herself on a nearby table. Her hand came away with a fine layer of dust, and she shook away the residual dizziness to look around.

It was STAR Labs, but it was nothing like any STAR Labs she'd seen so far. The lights were off, the only illumination provided by blue-tinted light of the breech. There were cobwebs in the corners, and it was incredibly still, the breech behind her the only movement, but even that writhed in uncanny silence.

The emblem was an inconvenient size, too big to stick in her pocket, but it was something to show Zoom to prove she'd done what he told her to and she couldn't leave it behind. She tucked it into the waistline of her pants at her hip, to free her hands.

Her footsteps as she made her way out of the room and into the hallway were muted by the dust that clung at the edges of the hallways, and she didn't find any lights on. The power to the building had been cut, if she had to guess, and she had to make her way along with one hand on the wall and the other outstretched, trusting her knowledge of the building to lead her to the cortex. If anyone was here, she would find them in that room.

The skylights high above her head let light stream into the cortex, even with all the lights off. One lone chair remained behind the desk that usually contained the computers, but now there was nothing. She trailed her fingers down the surface as she rounded it, leaving long swipes in the dust that filled over with frost. The medical room was empty too, save for a few shelves that looked like they couldn't be moved.

If Flash had a base of operations, this wasn't it.

She dropped into the chair behind the computer desk as the chill settled deep in her bones, wrapping her arms around herself in lieu of having anything to pull the heat out of. She was assuming there even was a Flash in this world, and part of her said she should walk back through the breech, write this universe off as nothing important. Curious, she stood up and made her way into the medical room. With the tables cleared away, the windows were the most eye-catching feature of the room, and the dust rose in little puffs around her feet as she made her way over to look out. She'd half-expected to find a twisted skeleton of a city, everything as abandoned as STAR Labs seemed to be, but the city looked the same as it always had. Below, people went about their business under the bright sunshine.

Leaning against the window, Killer Frost weighed her options. The first and most appealing option was going back to the breech, crossing back through and try her luck with finding her home like that.

She could go and sit by the breech and wait for Zoom to take her home. She tried not to think about the fact that he hadn't reached out, even though she had been through the breech three more times since he had dropped her in a different universe. For all she knew, she was getting farther from her home universe every time she went through the breech and he didn't know how to get to her anymore.

Or she could go out and see if this world had a Flash.

She was starting to question what that would accomplish. She had proof she had killed a speedster, that was all Zoom had wanted, killing more would make him happier, prove she was still worthy of his trust, but...

But she didn't really want to kill the Flash. Not when the Flashes she kept running into weren't even the one she was supposed to be hunting and they hadn't threatened her, hadn't done anything to deserve being killed. Usually they had done the opposite, and-

A flicker of light in the corner of her eye made her head snap toward it, but there was nothing when she turned her head. She swiped away the frost that had resulted from leaning on the window, but there was nothing there, not even the light trail of lightning that typically accompanied a speedster's departure.

Sighing, Killer Frost turned around, about to go back to the breech and try her luck with another universe when she felt the crackle in the air that she had come to associate with the arrival of a speedster racing along her skin, the pressing feeling as the air compressed itself, but there was something wrong. This one was too fast, even for Zoom.

There was a sound like a small explosion when he skidded to a halt, taking most of the room to accomplish that, but even then he didn't stop moving, constantly shifting in place, moving from side to side and shaking all over until the edges of his silhouette were blurred. From what she could make out, he was staring at her, and he might have said something, but all that reached her ears was a high-pitched static, like a recording on fast forward.

"Flash?" she asked, taking a step forward. In a flicker of movement, too fast for her eyes to process, he vanished, but the static feeling on her skin, like a storm brewing, didn't leave and she turned around. He had only moved to the other side of the room. "Barry?" she tried.

There was definitely a reaction this time, and he flickered out of sight into a blur of lightning and reappeared inches in front of her, only barely halting in time to prevent crashing into her. The realization that he couldn't control it entered her head as abruptly as if someone had hit her with it.

She set a hand on his chest and built ice around him, slowing him down a little. Flash's head snapped down, then back up in a blur, and more of the high-pitch static whine came out of his mouth as he spoke too quickly for her to understand. She couldn't even make out enough of the tone to determine if he was warning her off or pleading for mercy.

"It's okay," she told him. However easy it would have been to kill this version of Barry, she rationalized that even Zoom would not have killed him. Stolen his speed yes, if he had gotten that trick to work while she was gone, but this one didn't seem to be in control of himself enough to actually fight. Zoom was many things, but murderer of those who couldn't oppose him and wouldn't get in his way wasn't one of them.

He touched the place where a perfect imprint of her hand was visible on his chest in ice, then looked up at her, the motions little more than wisps of lightning. More of the high-pitched noises came out of his mouth, but no intelligible words.

"Can you understand me?" she asked him.

More of the sounds that were closer to static than conversation. He might have nodded, but it was lost in the general vibration that encased him. She collected one of his hands into hers, careful to minimize the heat she was taking. She hardly needed to regulate. Even for a speedster, he was burning up, the patch on his chest already melted and rapidly evaporating.

"Barry," she spoke as quickly as she could, "you have to slow down."

She might have been imagining it, but she thought the flickering around him decreased before it sped up again.

"Can you slow down?" she asked, then realized the error inherent in asking simply that and took a step back. "Okay, go to the windows for yes, the shelves for no."

The lightning trailed him as he flickered out of sight, reappearing by the shelves.

"Do you want to?" asked Killer Frost.

A breeze ruffled through her hair as he switched sides of the room.

"I can help you to slow back down," she attempted, "Will you trust me?"

There was flicker of lightning in front of her, then he reappeared by the windows before returning to the space in front of her.

Setting both hands on his shoulders, she took a second to relish the warmth that seeped up her arms before steeling herself for what she was about to do. "This might hurt," she warned, and pulled, hard.

She had been a doctor once, a lifetime ago. It was part of the reason Zoom had chosen her. In addition to having a useful gift, she could patch either of them up after a run-in they couldn't escape or run circles around. Zoom had always healed quickly, but by time he had taken her through the breech he had gotten good enough that the only injuries were gone by the time he returned to his lab, so she hadn't used these skills in months and cryogenics had never been her specialty, but at this point she'd had enough first-hand experience to almost make up for that.

She knew what she was doing, in theory at least, taking heat to slow down the cell functions without allowing ice crystals to form and rupture the cells. She'd never actually tried to freeze someone without hurting them, it wasn't the sort of thing Zoom had favored, but the principle should hold.

It was agonizingly slow work, and were it anyone but a speedster, it wouldn't have worked. If it was anyone but a speedster, she wouldn't need to be doing this. Several times she had to stop completely to let things come to equilibrium, but after several minutes, she looked up at him and he was in focus, slowed down enough that she could see an expression somewhere between shock and awe.

She didn't dare take her hands off for fear that if she stopped completely, he would revert back to that faster state.

"How did you do that?" Barry asked, voice hoarse with disuse.

She drummed her fingers on his shoulders, ignoring the question for the moment. "If I let go, will you start speeding up again?"

He hesitated, then shook his head, slow and deliberate.

Carefully, she took her hands off him. The flickers of lightning were still there, sprinting him up and down him, and he was still shaking ever-so-slightly, but he showed no signs of vanishing into the speed again. "I have powers too," she told him.

Barry sat down, stirring up a cloud of dust, and slumped with his head on his knees. "More like a curse." Now that she could see him and not just the general impression, she realized he didn't look like the Flash. Instead of the suit, he was wearing street clothes that were burned in multiple places, and he was barefoot and far too thin.

Ignoring the dust, she sat down next to him. "I thought I was going crazy," he confessed, "no one knew it was me. No one could hear me."

He was starting to vibrate again, and she leaned against him and drew out more heat, pulling the kinetic energy back down, slowing him down again.

"For a while after the accelerator exploded, I didn't know I had powers," she told him, voice soft, and he picked his head up to look at her. Something about this moment felt too fragile and precious to break with loud voices, "Then I was locked in a freezer. I thought I was going to die. I should have died, but instead I woke up the next morning able to do incredible things."

He looked away, drawing something in the dust on his other side. "But you can control them."

"Not at first," she answered, "I froze everything and everyone I touched for weeks, but now-"

There was enough moisture in the air that she could easily pull together a snowflake the size of her palm. Tipping her hand, she showed it to Barry.

"How did you manage?" Barry asked. He had started leaning into her, but he didn't seem entirely aware of the gesture, and she dropped her head onto his shoulder. She hadn't had a chance to just sit with a speedster while she had her powers since she'd left her home universe.

"Someone gave me a reason to use my gift," she replied, "he wasn't afraid of me, of what I might do to him." If nothing else, she owed Zoom for that much, even if she had been terrified the first time she'd seen him.

She'd been hiding from everyone, scared of hurting them, when Zoom had walked through the wall in a flurry of blue lightning and said hello. She still didn't know what had brought him to her, if he'd been looking for her or had stumbled on her by accident.

She'd scrambled backward, holding up her hands to ward off the man who'd spoken, crying out for him to stay away and not sure if she was warning or pleading. He was dressed entirely in black, with a face like death, and blue lightning was still crackling around him where he had just walked through the wall.

He'd laughed then and came closer, crouching before her where she had pressed herself into the corner. "Are you frightened of me?" he'd asked, the double-tone of his voice resonating through the room. He came a little closer then, close enough she could feel the heat trailing off him. She'd had to catch her breath and yank her hand back where she had started to reach out, for him, for that heat.

"Interesting," he'd observed, and she remembered one hand reached out to catch her chin, pull her eyes up to his, and she gasped at the warmth pouring out of him, tugging more in. It felt amazing, like water after a desert, filling a need she hadn't known she had.

"There's a good girl," he'd soothed, "you won't hurt me."

He had slipped the other hand onto her wrist, released her chin and stood, pulling her with him. Using that leverage, he pulled her to him. She went willingly, wrapping an arm around him, desperate for the heat. So far he seemed to be fine, unlike anyone else she'd touched since the accident, and she had allowed herself to breathe a sigh of relief. Maybe this curse was lifting.

"I'm Zoom," he'd told her, "and you're going to be just fine now." And then he'd started running, taking her with him.

"You're going to be okay, Barry Allen," she said, pulling her thoughts back to the present, "one step at a time."

"Thank you," Barry breathed back, and let his head rest on top of hers.

How long they stayed like that, she didn't know. Long enough for the sun to noticeably change positions in the sky, and long enough that she stopped actively pulling heat from him, trusting he could stay at that speed without her interference, but without a watch or clock in sight, it was impossible to say.

"Where have you been?" he asked, some time later, "I haven't heard of anyone with ice powers before now."

She braced herself and stood up. He didn't immediately start speeding up when she stopped touching him, which she took as a good sign. "I'll show you," she offered.

Barry took the hand up and nearly toppled into her, legs not used to operating at human speeds. She caught him as well as she could, but he nearly sent them both back to the floor.

"Better?" she asked after a second, when neither of them was in danger of falling over.

He was smiling when she looked up, the same sort of perplexed smile she remembered from a couple of universes ago, when she didn't quite remember what a smile felt like on her face, and her heart broke just a little for him.

"Come on," she urged, knowing it was better not to draw attention to the expression, and started toward the breech room.

Barry made no move to pull away as they walked down the hallway, even though his footing was perfectly steady. She understood that clinginess, after not being able to touch anyone for less than two weeks, she'd been desperate, she could only imagine how much worse it would have been if it had taken Zoom months to find her.

"That is where I've been," she said when they arrived at the room containing the breech, and shot out a bolt of ice at the space she remembered it being. The breech writhed into life in the empty space, flooding the room with a soft blue light.

"What is it?" he asked.

"My way home, I hope," she replied. It was safe to tell him that much, at least.

"I have to go," she slipped out of his grasp and the chill came flooding back into her, "find someone you trust to keep you grounded, but Barry," she waited until his eyes, starkly green in the glow of the tinted light, caught hers, "don't be afraid to run." She turned and started for the breech.

Something snagged her hand, and she had to look back, even though every moment spent near the breech increased the likelihood that Zoom would find her. Barry was holding her fingers tightly, anchoring her against the tug of the breech. "Don't go," he said, the words just slightly too fast, "please."

It was nothing like when Zoom gave orders, but she wanted to do what he said. She could stay here, in this universe, with this Barry and be happy. She could give him a reason to keep slowing back down, and he would keep the chill at bay.

But then, Zoom was out there in some other universe, and he wouldn't stop until he'd found every Flash and killed them. If she stayed here, she would have to either kill him or watch him die when Zoom caught up to her, and this one who didn't know how to control what he was doing was not someone that posed a threat to Zoom's title. She couldn't stay here and watch him die.

"I can't," she said, and stepped backward toward the portal. He took two steps with her, and it was only when she was suspended in the breech that he let go. Her last view of that universe was Barry's face, and he looked like his heart was breaking, and then he was gone and she couldn't have said if he had sped away or the breech stole her sight of that universe.

She hit something, hard, the collision sent her spinning, and all she could do was curl up on herself and wait for it to be over until suddenly, the soundless whirl of the breech was gone.

Killer Frost pried her eyes open and found she was tumbling toward rubble, hundreds of feet from the ground.

* * *

 **Information for the universe:**

Eobard died in the particle accelerator explosion, so Barry was never transferred to the care of STAR Labs. He woke up out of the coma and thought he was going crazy, because he just kept speeding up and didn't know how to slow back down, and no one knew to hunt him down and tell him what was going on.

 **Still taking creative liberties with the biology of speedsters, apologies to the biologists. Because this one took longer and chapter 6 is short, today is a double update. Thanks for reading, next chapter will be up in a few minutes.**


	6. Lesser Evils

She had never tried to create something that could possibly hold any sort of weight while she was falling, but right now it was learn or die. Her creation fell at the same rate she did, until she shoved it downward, pushing more ice after it, forcing it to go faster than she was until there was a jarring sensation back through her as it hit the ground. She worked a ramp under herself, and then she was sliding, too fast, still too close to vertical, and it was a desperate struggle to keep ramp under her, but she wasn't free-falling anymore.

The ground came up faster than she had realized, and she went spilling out across the broken chunks of concrete and rock, landing on her left side. It was still a hard landing, and she was going to be colorful tomorrow morning, but she was alive, so she'd count it as a victory. Slowly, so as not to jar anything that might possibly be broken, she brushed the remains of the ice off her and sat up. One hand flew down to her hip, and she breathed a sigh of relief when she found the emblem still there. It didn't seem broken, but she was going to have an enormous circular bruise where she had landed on the thing. Inventory done, she looked up.

She was sitting at the bottom of a crater, the sides stretching out and looming up. It was enormous, like something had just come along and scooped out a chunk of the world and taken it elsewhere, leaving behind the crumbs. Her entire left side throbbed when she went to stand up, but it held her weight, and after a moment of looking around, she picked the direction that looked the flatest and started walking.

It took nearly half an hour of picking her way over rubble that shifted under her with every step, trying and mostly succeeding not to lose her balance and slide backward, before she reached the top of the crater. The ground before her stretched out in a series of rolling hills, with only scare vegetation dotted around.

"Stop," it lacked the double-tone, but by now she would know Barry's voice anywhere, and she turned to him. There was a tiny part of her that was hoping this one would give her a reason to kill him, but a much larger part hoped this one stayed true to form. At the rate she was going through them, leaving all the Flashes she was supposed to be killing alive in her wake, Zoom would never understand, but killing one now would feel too much like betrayal. She didn't quite want to think about who she would be betraying.

The costume was the same dark red, skintight thing she was getting used to, but it wasn't as clean as the others she had seen. His suit had been ripped in places and obviously patched, the scraps not quite the same color, the stitching irregular, done by hand rather than a machine, and one of the lightning bolts on the sides of the mask had been ripped off and not fixed.

"Barry," she greeted, starting to go to him.

He took a step back in response, and she stopped dead in her tracks as he shoved the mask back. She knew the face, but at the same time she didn't. This one had a scar slicing across the left side of his face, starting at the bridge of his nose, barely missing his eye, and cutting across his cheek before trailing down his jaw. How deep would that have to have been, to have left a mark like that when he healed as fast as he did?

"How are you alive?" his voice sounded hoarse, from disuse or dust, she didn't know, but it was the voice more than the words that made her stop. He sounded like a caged animal, and he looked like he was about to go blasting off again at the slightest movement. He looked older, more worn, than any other Flash she had seen so far, and it wasn't just the scar.

'By not dying' was obviously not the correct answer here. "Should I be dead?" she asked hesitantly.

"Yes," the word was flat, too much or too little behind it for her to tell what he could be feeling about that. "I'm so sorry, but you were one of the crazy ones Cait, and you were supposed to be dead."

A few small pebbles shifted underfoot and her side throbbed as she took a cautious step forward, but Flash didn't back up this time. "What happened here Barry?" she asked. Gingerly, she put a hand to the spot that was hurting the worst and chilled it.

"I always thought that Eobard was horrible for destroying my family," he said by way of answer, "but I never thought he would get worse on the day he died, was unmade, whatever."

She took another step forward, and he vanished from the spot. Only the barest flicker of lightning to show where he had gone. She spun in a complete circle, looking for him, and found him standing at the edge of the crater. "What happened?" she repeated, tone low and soothing, the sort she would use on a cornered animal. It was a little ridiculous, they were on a flat plain, Flash could escape in any of three-hundred and sixty directions and there was no way she could catch him if he decided to run.

"The end of the world began," he answered. He turned around, and in another barely-there flicker of lightning he was gone from the spot.

Flash's voice made her jump this time. She hadn't heard or felt him come up behind her, and yet when he spoke, he couldn't be more than few paces behind her.

"You must be a ghost, Caitlin," Flash said as she turned, "but it was good to see you, one last time. I'm sorry for how everything ended."

He was barely three paces away, and for another of her heartbeats, he stayed frozen, looking at her as though he might never look enough, as if he was seeing right to the heart of her. It made her feel simultaneously hollow, exposed, and priceless. Then, before she could do more than shift her weight to start to step toward him again, he was gone, turned and ran faster than she could hope to follow.

She looked around that plain, at the rapidly retreating trail of dust that was the only remainder of Flash. She would never catch him, and there was no incentive for him to come back. The only thing in sight was the crater, and if there was no one here, there was no reason for him to ever come back. She didn't know why he'd come here in the first place.

This time, she made a bridge, with pillar supports, leading up to where the breech floated high above the city. Maybe it was the lack of buildings to lend perspective that made the crater feel so much deeper, in addition to being a crater

Killer Frost paused at the top of her creation, a step from the breech, and looked back. She was half-expecting Flash to come and prevent her from crossing back into the breech, question her further about what had happened, how she had apparently returned from the dead, but her pathway was clear. Her gaze shifted down toward the edge of the crater to find a lone speck that could have been Flash or could have been simply a trick of the light.

In a chill that went to her bones, the kind that had nothing to do with how much heat she could absorb, she realized she didn't want to try and catch him. Not if ending this twisted game of tag meant she would have to kill him at the end. She was done trying to kill the Flash.

She turned back and fled the last two steps, running from the thought as much as the mangled universe she had been dumped into.

Even after so many universes, she still wasn't used to everything changing in a few steps. The breech thumped her around, knocking her into things she didn't want to think about, and then spat her out.

For one furious second, she thought she had missed the breech, because the ground was still hundreds of feet below her and she was falling again. The differences rapidly made themselves obvious though. She was falling toward skyscrapers now rather than an empty crater, and Central was spread out below her, people below stopping what they were doing as they noticed her.

It was harder than it ought to be, to pull up enough ice to form something, but she couldn't remember the last time she had used her gift that much without drawing off someone. Thankfully, the building she was now falling past made a good anchor point.

She wrapped the incline this time around the building, rather than a single pole, and she could do it at a less steep gradient. She was still a few floors from the ground when she came across window washers and had to curve out to avoid getting tangled in the strings of their washing unit.

The ice broke and she was falling again, doing her best to keep her body limp as she worked on something else.

A blast of wind from below caught her, and twisted in midair as much as possible as her fall slowed. Flash was standing there, arms a blur as the wind to catch her was generated. She came to rest on the ground in front of the building, a lot more gently than she had expected when she first realized she was falling.

"Nice slide," said Flash from behind her, "if you could possibly wave your hand and undo that?"

She must have hit her head at some point, because her vision was wavering. The world kept tipping when she moved. It was starting to get clear again now that she was sitting down, but the Flash didn't look quite right.

"Barry?" Killer Frost asked, extending a hand toward the hero as she tried to focus and see. The Flash froze, midway through reaching to take that hand.

"What?" the words came out in the double-tone Zoom had used so often, but even with that disguise, she could tell something was different. The tone was too high, the cadence off. This wasn't Barry.

She put a hand to her face, trying to scrub away the dizziness. It worked a little, leaving her to blink up at the speedster with clearer eyes.

The Flash gasped and then tugged off the red mask.

It was like looking in a mirror. Flash was her, she was Flash.

* * *

 **Extra Scene:**

"Was she there?" Cisco asked, hardly looking up from his papers as Barry let himself into the command center. There was no name attached, neither of them had said her name out loud for weeks, but he knew who Cisco was talking about.

"Yes," the speedster answered shortly, moving over to the nearest table, covered in notes. Some of them were crossed out, others highlighted. Cisco's vibes, predicting the next catastrophe as best they could. "She was. Thank you, for closure."

"No problem," Cisco reached up and circled a section of the map in the bright orange marker that happened to be in his hand. "Calculations say they'll strike there next. Tell the red squad to be ready to move at eight-twenty tomorrow morning."

"Are you sure this is the right thing?" asked Barry.

Cisco looked up, meeting his eyes, and Barry wanted to flinch. Since the singularity had devoured Central, Cisco's vibes had prevented a lot, but he had the unique opportunity of seeing the other side, where things did go wrong. The engineer woke up screaming most nights, though it was hard to find anyone nowadays who didn't have nightmares.

He turned his haunted gaze back to his papers. "I've seen what happens if we don't."

There wasn't any way to argue with that. "I'll tell them," Barry said, and ran off.

* * *

 **Information for the universe.**

Firestorm hesitated, unwilling to let Clarissa and Caitlin watch them die, and Barry couldn't keep the singularity totally contained. It ate Central before they stopped it, and the world just went further downhill after that.

 **Thanks for reading, and watch out for the next chapter soon.**


	7. Guy in the Glass

Flash pulled her mask back down over her face and offered a hand up, but Killer Frost pulled herself to her feet without taking the help.

"Who are you?" Caitlin asked, as she brushed off dust from the abandoned STAR Labs and bits of rubble from that destroyed world.

"The short answer," she replied, giving up on getting it all off. She and her clothes would just need to be washed, "is I'm you from another universe. My name is Killer Frost."

Even with the mask covering half her doppelganger's face, she could easily imagine the disbelieving look the other woman was giving her. "Another universe?" Caitlin repeated slowly.

"Trust me, Caitlin," she said, "I'll tell you later, when we're back at STAR Labs."

"What about your ramp?" the speedster asked.

Killer Frost looked up in the direction Caitlin had indicated. The icy slope above their heads clung to the side of the building, curving out of sight on one side. "My powers can't reach it now," she said, "it will melt."

One of Caitlin's hands went to the side of her head, and she listened for a moment before fixing Killer Frost with a searching look. "I have to go deal with something," she said, "Cisco will be expecting you at STAR Labs." And she rushed off in a blur of lightning that was closer to white than the yellow-gold she was accustomed to seeing Flash have.

This Central wasn't as high-tech as her own, no high-speed trains, and the towers of STAR Labs seemed to be more damaged than usual, but there had been extra security added. The sensors at the doors of STAR Labs wanted her thumbprint, and the light beeped green when she gave it, but thankfully the security didn't care about her eyes. Though she had the same fingerprints as Caitlin, the ice in her eyes would confuse a retinal scanner.

"So," Cisco spun around in his chair when she walked into the cortex, pointing the straw from his drink at her, "you're Caitlin from another universe?"

"More or less," Killer Frost confirmed. She had been Caitlin once, before her life changed so drastically, but the genetics would still say she was Caitlin, no matter what her name was. The engineer gave her a befuddled look, but he didn't have time to comment, because then Flash stopped next to her in a rush of wind and lightning, and Cisco almost dropped his orange soda all over the floor, looking back and forth between them.

"I have got to stop making plans on Tuesdays," he said finally, "everything crazy starts on Tuesdays."

"Which is why Barry and I have date night on Wednesdays," Caitlin said matter-of-factly. She leaned her hip against the edge of the desk, crossing her arms, and turned her attention from Cisco to Killer Frost. "Another universe?" she prompted.

She shifted her weight, wincing a little as the motion pulled at the side she'd landed on. Pressing one hand gingerly to her ribs, she let ice creep across her skin under her shirt. "I fell through a breech, a fissure between the universes," she explained, "and wound up here."

"Prove it," Caitlin said.

"Your print scanner let me in," Killer Frost replied, "If your version of Barry Allen is anywhere near as involved as he's been in some of the others, you know the odds of the same print coming from two different people. If you want to check, you and I have the same DNA too."

Her doppelganger didn't looked convinced, but Cisco turned around and started typing on the computer, pulling up what was probably the logs for the doors.

"Her prints match yours, Caitlin," the engineer confirmed, "either she's telling the truth or she's a perfect copy, which," he added to her, "would be really cool. Kinda freaky, but cool."

In a flurry of the white lightning, Caitlin sped out of the room, returning seconds later with a large sheet of paper that she laid down across one of the other tables. "Assuming you're telling the truth about the breech," she started, and Killer Frost crossed over to see she had a map of Central, "you came through here." Caitlin touched the spot where the breech had opened, and looked up at her. "Where were you on the other side?"

Killer Frost pulled one of the chairs around the table and took a seat. "The locations usually match on either side of the breech." A flick of her fingers raised a skyscraper out of ice on the map where Caitlin was pointing. "I went through above there, so that's where I came out. There's also one in the bank and in STAR Labs, and I'm sure several more."

Her time in this universe would be easier if the speedster didn't mistrust her so much, and she wracked her brain for something to prove what she said. "Barry likes to sing while he works," she told Caitlin then, quiet and only for her ears, "but only when he thinks no one can hear, and Cisco was disappointed that he didn't get to give Hartley Rathaway a code name, even though he approved of the name Pied Piper."

There was silence from her doppelganger, and when Killer Frost looked up, she found Caitlin looking at her. For a moment, their gazes held, then Caitlin smiled, a small thing that just curled the edges of her mouth, and nodded. "I believe you. I just had to be sure. Everyman fooled us twice, and Barry was tearing himself up about Wells after he betrayed us."

"The bank and STAR Labs, you said," the speedster changed the subject, bending back over the map, "What about the one you just came out of?"

"Those are the ones I've been through consistently," Killer Frost replied, "Central City in the universe I just left had been destroyed, the only portal correlated to that-"

Her explanation was interrupted by a rap from the hallway and Barry called out, "I brought lunch."

She looked up and he was standing in the entrance to the room, holding up a paper bag and watching the occupants with a smile on his face. Abandoning the map, she started to go to him, only to halt before she even stood up as she remembered that if Caitlin Snow was the Flash in this universe, Barry Allen was not a speedster.

"Caitlin?" he asked, even as he set the bag on the desk near the computers. He sounded unsure of the identification.

"Killer Frost," she corrected.

There was a flicker of lightning at the edge of her vision, the paler white-gold she was starting to associate with her doppelganger, and Caitlin halted beside Barry, tucking flyaway strands of hair behind an ear. "Barry, this is Killer Frost," she said, "Killer Frost, meet Barry."

"Okay," his gaze kept flickering around the cortex, jumping from person to person, even as he reached out to take her hand, "why does she look exactly like you?"

"She's Caitlin from another universe," Cisco called across the room, "Not the weirdest thing we've seen all month. Did you tell them no mustard?"

Barry pressed a kiss to Caitlin's cheek, the gesture quick and casual, then turned to root through the bag, pulling out burgers. "Here," he tossed one underhanded to Cisco, who caught it with practiced ease, "onions and no mustard." He handed another to Caitlin, then turned, and Killer Frost only just caught the one he tossed to her. It was still warm and she hadn't eaten in- she didn't actually know when she'd last eaten, several universes ago, but she hadn't realized how hungry she was until she tore in.

Between bites as they all ate, Barry was filled in with everything Cisco and Caitlin knew, and she filled in what she was willing to tell them at the moment. Somehow, she didn't think that revealing an alternate version of the man her doppelganger was dating had sent her to kill speedsters would go over well.

"And I desperately need a shower," she concluded, licking grease off her fingers, "if that doesn't impose too much."

"Nah," Cisco stood up and went into the other room. "Little help," he called out after a second, and Killer Frost went to go see what it was.

He had opened a closet in the treadmill room, and was tugging on a box wedged between the frame and the shelf. She reached up, careful not to touch him, and pulled on the other side, and together they got it onto the floor, where Cisco made short work of untucking the flaps where they had been neatly folded over each other. "I knew these would come in handy someday," he said, standing up with a bundle of grey fabric in his arms. He piled this into her arms.

"Clothes," he told her, "there should still be towels and soap in the bathroom, down a level, in the hall to the right."

After a few wrong doors, she found the bathroom Cisco had mentioned. She shut the door, looked up, and found herself staring into a mirror.

The first time she had seen herself after she received her powers, she had freaked out at seeing a stranger reflected there and broken the mirror. She still wasn't sure if it was the ice or the flailing hit that had cracked the glass. Zoom had never been big on pictures, or mirrors, so it had been easy to avoid looking at herself after that time.

Her reflection didn't seem so strange now. She was paler than she had been before her powers, her lips white, or a very light blue, and her hair blonde. The biggest change though, was her eyes. She knew the ice in them had turned them blue, but she hadn't known that ice glinted in the light, changing to white in places as the light caught it differently.

The clothes, it turned out, were grey sweatpants and a similar sweatshirt with the STAR Labs logo on the front. Both were slightly too large, but much cleaner than the clothes she had been wearing. Those she ran under the water, then hung up to dry. It wasn't perfect, but in lieu of a washing machine, it would do.

"Using the data Cisco scanned from the breech in our basement," Barry was saying as she walked back into the cortex, "which is not a sentence I ever thought I would say, we developed a detection program to find others."

"We found a couple more," Cisco added, "but they keep fluctuating. The program's still running, so we'll find them all eventually, but for now we have four."

"Is there a way to seal them?" Caitlin asked, leaning over Barry's shoulder to look at the computer screen.

"Seal them?" Killer Frost repeated, making the inhabitants of the room jump.

"You said you fell through," the speedster answered, "but you're a meta-human, we don't know what the trip would do to someone without powers. Even if it doesn't, duplicates of people walking around could only create confusion."

"If we could shoot a pulse of exactly opposite frequency," Cisco said, looking up from the paper he was scribbling on, "we could create destructive interference and force the breech to close. It would require very specific wavelengths though."

She tuned out of the conversation as they started debating various ways to close a breech. If they closed the breeches, would that stop all travel between universes, or would it just seal them off at this end? Either way, she had to go through before they closed the last one.

After a while, Cisco stood up from the table and went to his workbench in the other room. Killer Frost trailed after him, leaning on the table and watching him fiddle with bits of metal and wires, not really making anything, just moving his hands so he could think. It wasn't terribly exciting, but it was slightly more so than sitting in the other room watching Barry pace and Caitlin drum her fingers, though she could still see that too through the glass.

"I take it they're not," Cisco made a gesture back in the direction of Barry and Caitlin that was probably meant to encompass the entirety of that relationship, "in your universe."

She made a noise that might be trying to pass for a laugh. Her relationship with Zoom was similar and yet so very different from what this Barry and Caitlin had that it was laughable. "The version of him in my home universe is called Zoom," she told Cisco, "and we were lovers, but we weren't-" she made a similar gesture to the one he had made, "that."

He accepted that with a shrug. "He's Zoom, you're Killer Frost," Cisco commented, without looking up from where he was turning a screw, "I wouldn't get to give anyone a code name in that universe. Hand me that set of pliers? The ones with the red handles."

Killer Frost set the tool he'd asked for into his outstretched hand.

There was a clatter as both tool and the device being wired hit the table, and Cisco made a gasping sort of sound. Her gaze whipped over from where she'd been staring into space to find him with his eyes wide and mouth gaping open, looking like someone had just electrocuted him. He stayed like that for a heartbeat, then he rocked the table as he toppled off his seat.

Her first thought, ridiculous as it was because she knew she hadn't taken any heat, was that she had iced him, and she scrambled around the table to check, calling his name.

He was breathing like he'd just sprinted a lap around the labs, and looking at her like she had sprouted horns. "I saw- alley- you- Barry-" he gasped.

In a whirl of lightning, Caitlin was on Cisco's other side. "What happened?" she asked, hands probing gently at his head, checking for -injury.

He shook the speedster off. "I vibed, off her," based on the way Barry, in the doorframe, immediately straightened at those words, it meant more than just a general feeling, "I saw Barry, in a costume like yours but black, kissing her in an alley."

Her heart sank as she realized what was happening. Somehow, he knew about Zoom, about the reason she had started traveling between universes. "He told her to kill the Flash, and she said yes."

Caitlin moved in a rush, speeding over Cisco, and she felt the speedster crash into her almost at the same time she felt her back slam against the opposite wall. A tiny part of her noted, almost absently, that Cisco had been wrong; the universe wouldn't end if she touched her doppelganger.

"Why are you really here?" the speedster demanded, "who sent you?"

There was no reason to hide now. "Zoom," she choked out, as the elbow in her throat pressed a little harder, "sent me to kill the Flash, but I couldn't. Not in that universe, or any since. The only one I could kill was Reverse-Flash, when he threatened my life. I swear."

For a second, she wasn't sure whether Caitlin was going to release her or not. The speedster scrutinized her and even without the elbow in her windpipe, she would have had trouble not holding her breath. Then Caitlin jerked away and she fell to the floor, coughing and taking deep gulps of air.

Someone, not warm enough to be a speedster, patted her forcefully on the back, and she nodded gratefully. It took several more coughs before she felt coherent enough to look up. Barry was crouched next to her, but Caitlin was hovering close on the other side, ready to react if she did anything. The idea was nearly laughable. She'd had dozens of chances since walking in here to do whatever harm she might have wanted to, and she was hardly going to start now.

"What's your gift?" she asked Cisco, looking past both of them to the engineer leaning against the table. He still looked paler than usual, but she didn't know if that was from the use of his gift or from what he'd seen. She didn't think Zoom was terrifying enough to prompt that extreme of a response, so she would guess it was the first one.

Cisco snorted. "More like a curse," he grumbled, "I can't control when the visions come."

"Sometimes when he touches people, or objects that were close to them, he sees things about them," Barry explained, "With you he saw the past, but sometimes he sees the future, sometimes the present. Dr. Wells described it as 'seeing through the vibrations between the timelines' before-"

Her mind seized on one of the words. "Objects?" she interrupted.

Barry nodded. "Yes. Helmets, weapons, things their owners had for a while."

"Like this?" She drew out the emblem she'd taken from Reverse-Flash and held it out toward the engineer. She didn't know if this would work, if it would even show him what she'd done to Reverse-Flash, but it was worth the shot.

Cisco reached out in a manner more reminiscent of the way someone would usually touch a live piranha than an inanimate object, and laid his hand on it. The shock was written across his face again as he gasped, and then it was over.

"I saw her kill Reverse-Flash," he confirmed, "she made sure Barry was okay, then left."

He looked at her one more time, then turned and strode out of the room.

"I'm not going to hurt you, any of you," Killer Frost told Caitlin. Her doppelganger looked like she was wavering, biting on her lip. "I had plenty of chances and I didn't. I just want-" she had to stop as she realized she didn't have a mission anymore. She had completed the one Zoom set out for her, and all that was left was- What? If she sat still long enough, maybe Zoom would come and get her, or maybe when she wasn't in the universes he'd left her in, he'd stopped looking. She didn't know, but-

"I just want to go home," she finished finally, "but I don't know how to do that anymore."

Caitlin chewed on her lip more and swapped a look with Barry that had a whole silent conversation in it. He nodded, and Caitlin reached down, offering her a hand back up.

"Help us close the breeches," she said, "and we'll see what we can do about getting you home."

Killer Frost nodded her agreement, not completely trusting her throat to speak.

By the end of the week, her bruises had faded from purple and blue to green and yellow, they had located all the breeches, and Cisco and Barry had come up with some sort of device that should close them. They had almost scrapped the design when Barry pointed out they had to channel way too much heat for the materials they would have to use, until Killer Frost countered that she could cool it back down.

And they'd discovered that the breeches only activated if Killer Frost or Caitlin went near them. The first theory was that they reacted to meta-human powers, but every single one remained stubbornly dormant when Cisco was nearby, and Barry asked a favor of one of the meta-humans they'd rehabilitated and remained on friendly terms with to get her to try. She teleported straight through the space where the breech was, but it didn't so much as quiver, let alone open a portal to another universe.

"Maybe it's just Caitlins," Barry suggested from where he was sitting on a crate, making final adjustments to the device they'd built. They had decided to start with the one on the docks, given that if something went wrong, this one was furthest from buildings and people were least likely to get hurt.

Killer Frost shook her head, not looking up from the miniature snowman she was building in the palm of her hand. "Zoom took me through, the first time," she reminded him, "and it opened for him."

"But," Cisco surfaced from his toolbox with a noise of triumph, holding a set of batteries that he started fitting into the control box, "it can't just be speedsters, because it opens for you."

She shrugged, and set the finished snowman into the line of miniature snowmen she was stacking along the edge of the crate they had put the machine on. The first one was starting to melt under the bright sun, leaving a spreading wet patch on the wood, and the others were in various state of decay.

"Ready?" Caitlin skidded to a halt next to the crate in a rush of air and static.

Cisco snapped the panel back into place and hopped to the ground. "Yep."

"Wait," Barry leaned over and kissed the speedster, very quickly, "For luck."

Caitlin smiled, small and almost shy, then pulled her mask up. In a rush of white lightning, she took her place by the breech, which flared open at her presence. "Ready!" she called out, and Cisco hit the button as she started doing laps around it, holding the breech open at the same size while the device calibrated and then, in theory, sealed the breech.

For the first ten seconds, everything worked perfectly, then the machine started whining.

"It's overheating!" Cisco shouted over the rush of sound and the whine of the machine, "do your thing Frosty!"

Glaring at him for the new nickname could wait until they weren't in danger of exploding. Killer Frost flung out both hands, pulling heat from the machine desperately. It glowed under the strain and started whining, the pitch growing higher and higher until with a small roar, the breech writhed, once, twice, then imploded, sucking them, several crates, and the entire contents of Cisco's toolbox toward it.

Someone started laughing, and then they couldn't stop, relief it had worked and fading adrenaline making the whole thing funnier than it would be otherwise. Eventually, they calmed down, picked themselves up, and Cisco went to check the device while Caitlin figured out if any of the surroundings had been damaged, leaving her and Barry to gather the scattered things that Cisco had been keeping in his tool box.

Killer Frost was reaching between two crates, chasing the last spool of wire that seemed determined to roll away from her when Barry set the box down next to her. "I think that's-" he broke off as she turned, producing the wire with a victorious flourish that she knew didn't reach her face, "What's wrong?"

She pulled her gaze from the handful of tools to Barry's concerned face. "If I don't go through before we close them all, I'll be stuck," she told him.

"You could stay here," Barry suggested, "if all the breeches are closed, Zoom can't reach you in this universe. You'd be safe, you could be whoever you wanted to be."

Killer Frost looked away, out over the water. Seeing him like this, with this Caitlin, reminded her a little of the way things had been with Zoom. She wasn't sure anymore if he had been in love with her the same way she had loved him, but he had cared for her when everyone else was afraid of her.

There was always going to be a part of her that loved him for that. She owed him enough that she had to find him. If nothing else, she could close the breeches in her home universe to stop him. She would deal with whatever came after that when that came.

"No. I can't," she replied, "I'll go through the last breech." And, all things told, it hurt to watch Barry so close and yet totally out of reach. Zoom's solution, she knew, would have been to kill Caitlin, but she refused to consider that as an option. "I loved him, or maybe I still do, I don't know, but someone has to stop him, and I know him best. If I can't reason with him, worst case, I can close the breeches in my universe and seal him in."

"What about you?" Barry asked.

She glanced back at him and managed to smile. "I can handle Zoom," she said, "I was around him for months and I'm fine, which is longer than anyone else."

He reached out and squeezed her shoulder, and she covered the hand with her own, very carefully not freezing him. Even without the heat a speedster generated, he was still warm in a way that had nothing to do with temperature. Replacing the tools, Barry lifted the kit and they went to join the other two.

The rest of the breeches were closed with varying degrees of without-a-hitch. The size of the implosion, they quickly discovered had nothing to do with how wide the breech was or how long it took to seal it, and they learned to hang onto something immobile after Barry got thoroughly scraped up being dragged along the pavement toward the closing breech

Halfway through, the machine needed repairs, Caitlin needed to eat something, and Killer Frost needed a break, so they all trooped back to STAR Labs. Caitlin did a food run, Cisco did repairs, and they shut the breech in STAR Labs over lunch before heading out again.

It was the middle of the afternoon when they reached the last breech, in an alley near downtown, and Killer Frost stopped and just stared at it. Her presence nearby made it flare into life

Barry pulled the bag that he had retrieved from STAR Labs off his shoulder and handed it to her. "This has your stuff, blueprints for the breech-closer, as well as notes from each of us to ourselves that you can use to persuade that you are who you say you are."

Very quickly, so she didn't freeze anyone, she hugged him, and then Cisco. There was something a little awkward in hugging your own doppelganger, so she shook hands with the Flash instead.

She cooled the breech-closer, which they still hadn't come up with a better name for, and took the last few steps toward the breech. Cisco flipped the switch on the breech-closer, and the breech started to shrink.

"It was nice to meet you," Caitlin called after her, and there was not a trace of anything but honesty there.

"Likewise," Killer Frost replied, and ran the last few steps, leaping through the breech. She felt the jolt as it shut rattle her teeth a few seconds later, then she was lost to the blue.

* * *

 **Information for the universe.**

Eobard/Wells recruited Barry to work at STAR Labs, to keep a better eye on him. So Barry was there the night the particle accelerator exploded and the lightning that was supposed to hit him hit Caitlin instead, making her the Flash. She woke up nine months later to find that only Barry and Cisco hadn't deserted Wells, who was not very happy that his precious future had been changed.

 **So I meant to have this out yesterday, and then my computer decided to restart and I redo a bunch of it.** **Thanks for reading, hope you enjoyed. Next chapter will be up soon.**


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